Does a Cake covered in buttercream and fondant have to be put in the fridge? If I make it today will it stay till pick up on saturday or sunday? or is that just too far inadvance?
I personally would not have the whole cake prepared for today for a delivery that is not for another 3 or 4 days. I like to bake and fill on Thursday, ice and decorate on Friday for a Sat cake. Wed would be okay to i think. You could always bake in advance and freeze the cake (wrap in a couple of layers of saranwrap then in heavy duty foil) and make sure you let it defrost properly (I like putting it in the fridge to do that). After it's defrosted you can that do all the other steps, fill, ice, cover in fondant and decorate.
I do not put cakes in the fridge (especially fondant covered cakes) after they have been decorated unless there are perishable fillings in it. Fondant will get condensation on it and will be a little wet and sticky when you pull it out of the fridge. I have read that if you do put it in the fridge than after you pull it out let it sit on the counter and dry up before you touch it.
HTH. P.S. Let me know if anything doesn't make sense to you.