Three locations could be the whole game, not the abandoned tutorial :) A wizard's mind doesn't need 40 rooms; it needs one memory that hits differently on the way back.
I'd try one object that changes meaning across those three rooms: first a strange key, then a clue to who owned it, then the choice to keep or return it. Reuse the rooms after that reveal instead of building more.
That's the small-story problem behind P.S.Me, our personalized gift-game project: the person matters more than the size of the map. Your wizard premise sounds like it could work as a tiny finished story.