Rem did a good buck on this game, he could subcontract. Some modders already know the game's code almost as much as Rem, they could do it as a paid job. most of it would be assets modifications and work has already be done to facilitate the integration of new edicts, passives and titles. the story narration and dialogs are already made in the game engine, it would be easy to add some. the only real job would be scenario, storyboard and additional art that need more than just tweaking (new endings, new sex scenes, new pose art).
I may sound like it's a fast and easy task, I know it's not, it may take time, but far less than beginning from scratch and he have now access to resources he didn't when he started developing KP.