Have the ability in late game to switch between mushrooms and fruitbats like skills for 10k. Though this can easily be switched on the computers save file, those with consoles do not have that option.
Heck, I'd pay a million or tons of resources to switch. I love my current longest save but wish I had the fruit bats now. I don't even go into the mushroom cave anymore, I just pretend it's not there.
I know that's a possible way to extend. But I don't have cabins in my main/long-term game and I don't want one in this.
Because we are here offering suggestions: I could imagine an expansion where you find a secret door in the basement that leads to the another cave (or the Mutant Bug Lair) which is usable as cellar.
BTW:
Especially in the Mutant Bug Lair one can't really do much. A few more adventures/secrets/features there would be cool. Maybe a secret room with another Altar of Yoba.