I think there is zero chance they'll cancel any of the episodes. This is the biggest money haul SE are going to get for a long time. FFVII Remake is now the third most watched game on Twitch, ahead of Just Chatting, Dota 2, CSGO, Fortnite, CoD, Hearthstone, GTA V, WoW, Animal Crossing, Minecraft etc. Only LoL and Valorant are beating it. Everyone is so far loving the game, they have zero reason to not complete the game. They might shorten the "added content" in future episodes if anything, but they won't cancel them. They've done episodic games before successfully, it should be remembered.

I browsed around online and the general feeling is that it should be around 2021 for the next episode. I'm not sure that's realistic but hell, some people think it could be as soon as this year because they think it'll be the equivalent of DLC. I disagree on that, they'll make it a full new game like Mass Effect was. So I think 2021-2022 is a reasonable expectation at this point, although I'll be a little disappointed if it's 2022 because I get the feeling by the time I finish this game I'll be wanting the next episode pretty fast.