I'd be a happy with a big patch, that actually fixes stuff instead of breaking it...
Apart from that, the game feels very much like this is still early access, especially act 3 is nowhere near where it could be. Because of this I think, a Definitve Edition with a bigger act 3 overhaul is likely.
I don't think we will get a full DLC, the story is very much selfcontained. Maybe something small, a quest they wanted to do, but didn't have the time for... More likely is that they start work on their next project as soon as BG3 is in a stable state. Based on the huge success I'd say, that is not the last DnD game from Larian.
