I have been reading about not putting royal icing decorations in the frige, my question is what do you do when you decorate the cake and use royal icing roses but don't deliver the cake until the next day? Let sit out or put in frige overnight? I have put the cake in the refrigerator overnight and so far have not had any problems with the RI roses, but don't want to push my luck. Any advice?

I put RI in the fridge all the time but it also depends on your climate etc..If you are typically a hot humid climate this may not work.I live in a dry climate so all my fondant/gumpaste and RI dries in about 1 day.

There is no need to refrigerate a cake if not serving right away, unless a perishable filling is used. Refrigerating a cake tends to dry it out, IMO>