Any idea if these can be made in advance and stored? I was thinking of wrapping them in foil and leaving them in the fridge til Easter.

I don't see any problem with refrigerating these until Easter. I would pack these in an airtight container in the fridge until Easter and then take them out and wrap them. Also, you might want to wrap them in parchment paper or a lined foil wrapping. Michaels's carries a sort of parchment lined foil candy wrapper sold in squares that I like. Happy Easter!