I still feel epilogues will all be in one big episode, not eked out piecemeal style.
Biggest reason why is think it about it this way; let's say the epilogue episode gives us the conclusion to the main story, the universal stuff we all know about, but only gives you the endings for Sage and Jill. The problem you have there is that it only satisfies part of the fanbase whilst also revealing the main ending to the game and thus potentially spoiling it for those not interested in or even not playing those paths. DPC would never want people to know how the story ends before getting the ending with girl(s) they want. He's also not just going to have the endings for each girl and leave out the universal ending until they're all done and I also don't think he'd do the universal ending and then each epilogue one at at time. DPC interweaves so much of this game that the universal and branch endings will surely be interwoven as well.
It might take a really long time to do all the endings in one episode, but one thing we know we about DPC is that he'll take however long he feels is needed to do that and not feel like he has to put out the ending in pieces just to keep people happy.
I admit that it would be pretty uncommon to spread epilogues out over multiple episodes/DLC, but it has been done before (I can think of 1 game but they charged money for the final epilogue dlc). Considering how many endings there could be however it could be expected to spread them over at least 2-3 epilogues/packs. What I currently think of:
- At least a DIK and CHICK ending per MG with probably a third independent ending based on TC. My guess is that NEUTRAL route's endings can be either the normal DIK or CHICK ending but maybe based on how many post-ep8 (or even total overall) major choices you made combined with your status
- 1-2 endings per SG that have a "confirmed" route
- Endings based on how often you had sex and with whom without ending in one of the above routes.
- Maybe 5 Zoey endings: 1 per switch from MG and 1 from others
- Maybe two "secret" fun endings: An extreme dark ending where MC comes a die-hard criminal like Vinny if you choose every DIK option (both major and minor), or an extreme positive ending where MC acts like an angel if you choose every CHICK option.
It's still possible that besides the already "confirmed" Bianca route and probable Cindy route, there will be more new last-minute routes added in episode 12 (Sally, Mel and Sarah come to mind, with if Sarah happens it will almost certainly be an open relationship)
Like Darkwen said, it could easily go to 50 and possibly even more.