Trying to do chapter breakdown now that we know some towns will likely be pushed to Part 3. Using this site's poll as our guide, let's say Rebirth will end at the Northern Crater since that's what most people think. I also like to be generous and will give each locale its own chapter.
Chapter 1 - Nibelheim Incident part 1
Chapter 2 - Nibelheim Incident part 2
Chapter 3 - Kalm / Badland
Chapter 4 - Chocobo Farm / Wetland
Chapter 5 - Mythril Mine
Chapter 6 - Under Junon / Polluted Coast
Chapter 7 - Junon
Chapter 8 - Cruise Liner
Chapter 9 - Costa del Sol / Vacation Coast
Chapter 10 - Mt Corel / North Corel
Chapter 11 - Gold Saucer
Chapter 12 - Desert Prison
Chapter 13 - Gongaga / Jungle
Chapter 14 - Cosmo Canyon / Cave of the Gi
Chapter 15 - Nibelheim / Shinra Manor
Chapter 16 - Mt Nibel
Chapter 17 - Rocket Town / Grassland
Chapter 18 - Gold Saucer revisited
Chapter 19 - Temple of the Ancients
Chapter 20 - Bone Village / Sleeping Forest
Chapter 21 - Forgotten City
Chapter 22 - Icicle Inn / Snowfields
Chapter 23 - Great Glacier
Chapter 24 - Gaea's Cliff
Chapter 25 - Northern Crater
Alright, 24-25 chapters (depending on how many we want to dedicate to the Nibelheim Incident). And this is without Fort Condor or Wutai. Not bad, but it's still 33% bigger than Remake (assuming chapters will have the same amount of content).
Let's consider the geography of VII's planet. Technically, Costa del Sol and the Gold Saucer are just hop, skip, and a jump away from each other. You can even travel between the two zones with the buggy in the original game. Is it wise to save North Corel, the Gold Saucer, and ultimately Barret's past for Part 3? I can't answer that, but
I am looking for cuts, so out it goes.
Chapter 1 - Nibelheim Incident part 1
Chapter 2 - Nibelheim Incident part 2
Chapter 3 - Kalm / Badland
Chapter 4 - Chocobo Farm / Wetland
Chapter 5 - Mythril Mine
Chapter 6 - Under Junon / Polluted Coast
Chapter 7 - Junon
Chapter 8 - Cruise Liner
Chapter 9 - Costa del Sol / Vacation Coast
Chapter 10 - Gongaga / Jungle
Chapter 11 - Cosmo Canyon / Cave of the Gi
Chapter 12 - Nibelheim / Shinra Manor
Chapter 13 - Mt Nibel
Chapter 14 - Rocket Town / Grassland
Chapter 15 - Gold Saucer
Chapter 16 - Temple of the Ancients
Chapter 17 - Bone Village / Sleeping Forest
Chapter 18 - Forgotten City
Chapter 19 - Icicle Inn / Snowfields
Chapter 20 - Great Glacier
Chapter 21 - Gaea's Cliff
Chapter 22 - Northern Crater
Looking better. Thinking some more, there's nothing essential about Gongaga in the party's journey. The only time the player is required to be there is when Cloud wakes up after the Temple of the Ancients. Let's just say the party pursues Sephiroth north while Cloud is knocked out instead. Additionally, there's potential to move the Keystone away from the Gold Saucer. Honestly the key could belong to anyone or be found anywhere. Have the player backtrack to a hidden area in the Mythril Mine or something, that place could see more use. EDIT: The only remaining issue is Cait Sith. Admittedly, that's a pretty big problem to have... Let's just say he joins on the Cruise Liner instead. He's an entertainer for the high class or something.
Chapter 1 - Nibelheim Incident part 1
Chapter 2 - Nibelheim Incident part 2
Chapter 3 - Kalm / Badland
Chapter 4 - Chocobo Farm / Wetland
Chapter 5 - Mythril Mine
Chapter 6 - Under Junon / Polluted Coast
Chapter 7 - Junon
Chapter 8 - Cruise Liner
Chapter 9 - Costa del Sol / Vacation Coast
Chapter 10 - Cosmo Canyon / Cave of the Gi
Chapter 11 - Nibelheim / Shinra Manor
Chapter 12 - Mt Nibel
Chapter 13 - Rocket Town / Grassland
Chapter 14 - Temple of the Ancients
Chapter 15 - Bone Village / Sleeping Forest
Chapter 16 - Forgotten City
Chapter 17 - Icicle Inn / Snowfields
Chapter 18 - Great Glacier
Chapter 19 - Gaea's Cliff
Chapter 20 - Northern Crater
Sweet. 20 chapters. And this could even be brought down to 18 if you only dedicate one chapter to the Nibelheim Incident and combine the Great Glacier / Gaea's Cliff.
This pushes Fort Condor, North Corel, Gold Saucer, Gongaga, and Wutai to Part 3. And you know what? I think that's reasonable. If events were followed perfectly then Mideel, the underwater reactor, and the center of the planet would be the only new locations in Part 3 (again, assuming Rebirth goes up to the Northern Crater). Moving these locations to Part 3 ensures that the game will have plenty of new content alongside the revisits.
Exciting times!