I've felt Spectre had potential but that the execution was rather lacking. As such I've come up with a rough idea for a redo.
Keep Mexico:
"After Mexico Bond and M are having a chat. M points out that while Bond was able to thwart the attack, the way in which it was conducted is still being used as ammunition. We learn that Bond has been communicating with M about it. There's talk of a new program called nine eyes in the wake of multiple terrorist attacks, but at the same time they received messages from a mysterious figure hinting that there was an unseen hand behind the various attacks; attempts to track them down have been unsuccessful. Bond has been investigating one such potential lead in Mexico.
We see there's a lot of tension, as MI6 is still in hot water thanks to Silva's actions (and M's role in his fall from grace going public has only hurt more). About 18 months have passed since Skyfall. Bond, having found incriminating documents in Sciarra's laptop after he searched his house after the sequence, decides to go to rome to find more info.
I'd vastly shorten the rome sequence and focus it on getting Lucia to safety. The action scene is Bond and his car rushing to evade assassins with Lucia in tow. Bond presses Lucia when she's safe with Felix and she reveals that her husband was trying to track down a man called the Pale King. She gives Bond a flash drive that she recovered shortly before they left, which contains more information. Bond has Q combine the information with their own and they are shocked to discover that Mr White is the "Pale King". Q quickly tracks White down and Bond goes to meet him in Austria.
We cut to a meeting; the Spectre leaders are all masked in shadow and they discuss this latest development. Number 1 is unconcerned. Bond will lead them to Mr White. After all they have an agent inside. Number One is asked about the nine eyes vote (which is so far unsuccessful.) Number one ominously chuckles and says "that will soon be taken care of."
At this point, another terrorist attack rocks South Africa; we see the carnage and the misery inflicted in elaborate detail.
In Austria Bond arrives at an isolated chateau where White is hiding out. Bond breaks in, and overpowers Madeline when she tries to attack him. He refrains from killing her and he and White have a long chat; White tells Bond he must listen to him but Bond is not interested and demands how he knows what's going on. White explains that after Bond foiled the Bolivia operation Quantum was crippled and on the run. They were approached by a mysterious up and coming criminal named Blofeld, who offered to ensure their survival and resurgence if they sold out to him and joined up. While some of them did so eagerly White was suspicious and did research on him. What little he did uncover about Blofeld's past was enough to horrify even him (Blofeld slaughtered most of his fellow mercenaries to ensure his survival and left one alive to carry the "additional protein".) Ever since than White's been on the run, trying to find ways to bring Blofeld down with what little resources he has.
Bond realizes that Blofeld and the mysterious "Spectre" are the ones behind the attacks, which White confirms.
White reveals that he began to assemble a database containing information about Spectre that he's been slowly accumulating over the years; however he was diagnosed with cancer, and began to try and reconnect with his daughter. He also decided to use MI6 to take out Blofeld, hence why he sent M those cryptic hints.
"I should have realized you would figure it out on your own."
Unfortunately a team of assassins shows up and tries to kill White and James, as well as Mads. James kills them but White is mortally wounded in the shootout; Bond makes peace with his old foe before he dies as White apologizes for what he did to Vesper. At this point when Bond looks out he discovers that the second wave is preparing to blow up the house. Bond and Madeline narrowly flee the explosion and escape into the mountains.
Meanwhile the Nine Eyes vote occurs and the 00 branch is officially declared obsolete.
Act II
Later on in an villiage Bond and Madeline talk with Q over a laptop; Bond is suspicious as to how the assassins were able to track White given that Sciarra's information was incomplete. They realize that someone within MI6 is feeding information to the mysterious organization; Bond is informed that while they might be able to offer sporadic help Bond will be on his own for the most part. Madeline demands to go with Bond; Bond is at first reluctant since Madeline, while somewhat proficient, is hardly a skilled agent. Madeline successfully points out that she's the only one who knows where L'American is, and that Bond can't just leave her lying around, since Spectre's assassins might gun for her. Bond reluctantly agrees to let her tag along.
We cut to an Austrian city, where Bond and Madeline are walking through the streets. They have some discussion but eventually arrive at L'American. They get into the hotel room and look around. During this time they talk about their contrasting relations with Mr White. Madeline admits that she loved her father, but ultimately hated his criminal way of life. She cut off ties with him, but less than a week ago her father contacted her to reveal that he was dying of terminal cancer and he wanted to say goodbye to her. That was when James showed up. Eventually they find the secret room in L'American; it contains information about Blofeld and Spectre that White has gathered over the past few years. Bond copies the information and sends it to Q; Q informs them that everything has been shut down and 00 section is out of business. However, he'll try to do whatever it takes. Bond, realizing he's out of options, decides to go to Blofeld's base and take him down. Madeline persuades him to let her come.
In Tunisia Bond and Madeline spend time on the train like in the movie, having a chat, and becoming closer. However, Hinx attacks them while they're on the train. We get a quick fight sequence, and Bond is forced to choose between saving her or taking Hinx out. He saves her, but gets knocked out.
Act III:
Q, who has been monitoring Bond, is shocked and immediately reports to M Bond's dire straights. M has been trying to reveal the information Bond uncovered in Austria without luck, and sick of the stonewalling agrees to help. However, he realizes that they need help to go up against Blofeld. Q contacts Felix and M contacts several old friends in the army, assembling a covert strike team of American and British agents by pulling favors. They quickly head to Tunisia in order to rescue Bond. The question is whether they'll make it in time.
Bond wakes up bound in a cell, with several guards pointing guns at him and Madeline to ensure that neither of them makes any moves. Bond's gadgets have also been confiscated, except for the exploding watch (which they failed to find). Eventually, a tall, muscular women named Irma Bunt releases the two, and orders them to follow her. She leads them to a dark chamber, where the Karterhoff meteor is on display. Blofeld emerges from the shadows, describing the meteor like in the movie. He takes them to his control room, explaining the nature of his plan. To twist the knife in even further he taunts Bond with the fact that if anything, it was HIM who made it all possible. After all, it was gaining Quantum's resources that allowed him to get into the big leagues and he only gained THAT after Bond crippled the Tierria project. He also mocks Bond about Madeline, comparing her to Vesper. He further states that every woman close to Bond either dies or drifts away (Camille Montes). He also reveals that while Silva didn't directly work for him he did provide logistical support and weaponry for him to cary out his vendetta. "Raoul was a mad dog, so blinded with rage he'd do whatever it took. When I offered him logistical support he was all to eager to take it."
Eventually, we get to the torture room. Blofeld starts to torture them.....but just as the drills are about to enter Alarms start blaring and a massive explosion begins to rock the base. M and Felix have come through, sending a mixed team of US soldiers and British agents off the books. The chaos allows Bond to break free and attack Blofeld with the exploding watch like in the movie. Blofeld flees, badly injured and Bond goes in pursuit. He meets up with the commander of the operation (and Q who has tagged along), and tells them to go to the control room and access as much information as they can. Bond pursues Blofeld but runs into Hinx. They engage in a final showdown. Bond manages to defeat him by beating him to death with the Kartenhoff meteorite. The base goes up, but in the aftermath Blofeld's body is not found. Bond realizes that Blofeld is still out there. In London, C is arrested, as during the raid they were able to gather additional proof of his ties to Blofeld. Nine Eyes is shut down and the other nations that suffered from Blofelds terror attacks agree to combine their resources....only this time it's to bring Blofeld down. Bond meets Madeline; they have fallen in love but after almost watching him die Madeline feel they cannot be in a relationship. Not as long as James is part of the service and his life is in danger.
In the shadows, Blofeld swears that Bond shall pay; the battle has been lost but the war has just begun."
The sequel would have continued the Blofeld arc and seen their final showdown; the climax would involve Blofeld trying to recreate Vesper's death with Madeline, and Bond managing to free Madeline and save her before overpowering Blofeld. After a final dramatic face-off Bond spares Blofeld and allows him to be arrested and tried for crimes against humanity. Bond then retires and leaves with Madeline finally free of the ghosts of his past
This is kind of a rough idea