I don't think it would have to be a whole new game. You would change the starting point of the characters and allow them to explore in their own direction. A quest generator would be amazing but I feel Larian studios has done a fantastic job with existing content and previous games' side quests that the players could just engage with mostly existing content and maybe add more side quests over time.
I guess I would like to see the only main factor be full multiplayer with all custom characters.
