My brother is begging me to make him a cake for a party on a Staurday evening and he wants to pick it up on the Monday before. He lives an hour away and I will be out of town the rest of the week so that is the only timeline that will work. There will not be any perishable filling and it will be iced in buttercream and covered in fondant. Do you think it will be good 4 days later? Any suggestions for keeping it fresh?

Absolutely. I have kept a buttercream/fondant cake in the frig for up to 9 days and it looked and tasted fine. Make me wonder just how long it really would last in there??? I don't think I'll try to find out