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.