I've got to deliver my cake on Friday, but need to space out decortating this week b/c I work and only have time to decorate in the evenings.
Here is my plan-
Tues(today)- filled & crumb coated w/ buttercream (the fillings do not require extra refrigeration).
Wed- Make my MMF and possibly cover it w/ Fondant if not too early?
Thurs- Add all my decorations to the cake
Friday - delivery
Sat - is the party

It's 97 degrees here today in central CA. I don't know if I should stick my cakes back in the fridge today or at any point. My buttercream is a 1-to-1 ratio of butter & crisco.

You should make yr MMF a couple of days ahead. Make yr mmf before you bake the cake.

mmf should sit out at least over night to settle...to make sure you get a nice consistancy.

I think you're timeline sounds ok other than that, but with that high of heat I would definitely refrigerate

Ok thanks. I've never made MMF before so this is good to know. Can I refrigerate w/ Fondant? I heard not to or it will crack.

actually, the only thing you have to worry about with fondant is condensation. if you're able to get the humidity down in your fridge that is a good help. other than that when you bring it out of the fridge you are going to get that condensation and you may want to bring it out a couple hours before you have to decorate it so it's not slimy

I refrigerate fondant all the time and I do let it sit out a few hours to come to room temperature. I smooth my fondant using powdered sugar and when I put the fondant covered cake in the refrigerator it does have a thin layer of PS on it. I've never had a problem with the condensation leaving water marks on it. It does get slimy when it starts to come to room temp so if you do refrigerate it don't touch it at all or your finger mark will stay on the fondant and dry that way. I've never had an issue with the fondant being refrigerated and it could be because my area is super humid. I don't know if that makes a difference.

HTH!!!