This is a really cool theme, way outside of anything I'd considered and that's half the point of a jam!
I'm really keen to read more games that use tarot as resolution. I have a couple of decks knocking around that I've never really made full use of and would like to. I've never quite got through using it differently to a standard deck of playing cards.
I think Itch is a good platform because you can release a game that is in development and update it later. So, if you can get to a completeish stage, you could definitely still submit it for the jam.