See to be honest the more I think about it the less it makes sense for Part 1 to be "Just Midgar" unless they're planning more than three parts.
Assuming it's 3 games, the point made earlier in the thread about each game ending with a Jenova boss fight, and each game featuring a pivotal Sephiroth moment makes the most sense. With this in mind:
Part 1: Kalm flashback, Jenova fight on boat. End with cutscene travelling to next continent. The first half to 3/4 of the game within Midgar.
Part 2: Costa Del Sol to meteor summoning. It's end-loaded with the crater Jenova boss and another pivotal Sephiroth scene. And of course Aerith's "moment" occurring somewhere two-thirds of the way in to the game. I think it's crucial this doesn't happen at the end of any "part" because part of their original intention was to have the player feel her loss not just in a narrative sense, and from a gameplay perspective the impact is gone if they don't continue within the same game after this moment.
Part 3: Narratively a lot of the bigger set-piece moments would then happen here, but it's also the least chunky in terms of set-up storytelling because almost everything that happens at this point in the game is a continuation or reaction to things we already know (it is the conclusion piece after all).
If we further break that down very loosely into the three-acts (set-up, conflict, resolution) of traditional storytelling:
BEGINNING
FFVII:R1
Act 1: Introduction to the world and its characters, we learn about Shinra. Shinra take Aerith. (I suspect a shitload more exposition/ story/ missions in here)
Act 2: Our conflict so far in part 1 is with Shinra from the Avalanche perspective. We go to rescue Aerith and learn (a little) about Jenova and Sephiroth, which becomes more setup within an already set-up conflict. Within act 2 we resolve a minor conflict and toward the end of it move outside of Midgar. Depending on whatever works better, Act 2 either ends with the characters standing on the edge of that highway discussing "where do we go now?" or it ends at the resolution of the Kalm Flashback where they resolve to continue. I think at the end of the Kalm Flashback works better.
Act 3: Our resolution for R1:A3 is essentially "we know the true enemy's face" in that you fight Jenova for the first time. I think that could make for an excellent final boss but I also think they'll have to do something narratively to the moments between Kalm and the boat to make it all fit as a final act. I can definitely see it working though - Fort Condor for example can be used as a place for the characters to rest while making the journey to Junon. We'll potentially only see a slice of Junon here and more of it in a later game. The could put Yuffie somewhere in here but she'd fit much better in Act 1 of Part 2.
FFVII:R2
Act 1: The "set-up" portion here is the introduction to the rest of the characters and our character exposition story beats (Corel, Cosmo Canyon etc.). Act 1 essentially ends at Wutai, assuming they include that as a progression requirement (which they should IMO) and learning about the Keystone - in the OG this would be when you get the Tiny Bronco. Narratively it makes the most sense to wind up at Wutai before learning about the keystone. This means also that if they're keeping the Yuffie-steals-your-materia segment then you have to recruit her very early in this game, so that she's with you for a fair portion of time before the betrayal.
Act 2: This is probably the most easily defined "conflict" act. You look for and find the keystone, are betrayed, go through Temple of the Ancients, lose Aerith, track her down and the inevitable happens. Act 2 ends in the obvious place. They can likely add in story beats here that weren't in the original, such as the quest to find the keystone. I'm personally hoping for a bit more Cetra exposition at this point.
Act 3: Act 3 is just about loss and the world being flipped on its head in more ways than one. With characters that will be voice acted I'm really hoping they do this justice. If you're walking through the frozen tundra or hiking up the mountain the setting is such that it should be easy to have the characters VA's reflect the bleak atmosphere after the loss. The end of Act 3 is obviously Jenova fight - Cloud's breakdown/ betrayal - meteor.
FFVII:R3
Act 1: Easy set up at first. Tifa wakes up in Junon after a period of time and we learn the current state of the world. Here is where we might see radical change - they could remove the huge materia sub-plot entirely (not much of value is lost there) and give Tifa more time to lead the group before finding Cloud and handing the reigns to Cid. Assuming however that they keep that sub-plot, we'd see that playing out in Act 1. So essentially finding Cloud, Corel, Fort Condor (this would work better I think if Tifa leads and they find Cloud after dealing with the huge materia stuff in those areas first). Then we get Cloud's realisation/ recovery, the rest of the huge materia stuff (space etc.) and so on. Act 1 ends back in the Forgotten Capital with Bugenhagen.
Act 2: The conflict here obviously being Weapon, Return to Midgar, Hojo. Lots of room here for character resolution moments, I'm thinking Vincent/ Lucrecia, RedXIII/ Bugenhagen, Zack flashbacks etc.
Act 3: The end, pretty self explanatory.
END
Idk I think I might collect my thoughts better and write an opinion piece for the front page on this issue. But you get the gist, with this structure it would make sense to split them in that manner. They all end with Jenova/ Sephiroth, they all deliver pivotal character and villain-centric moments, and they're all fairly evenly split in terms of narrative length. The biggest problem is actually Act 1 of Part 3 because of the huge materia quest, but I have no idea how to include an underwater reactor and going in to space while also removing that subplot. They could always just write it better this time lol.
