If you have a moist cake recipe or are baking from a mix, and you've got any coat of icing on it at all, protecting it from air exposure it'll be fine. I do it every week, and our cakes stay moist and delicious. Icing is like saran wrap. Also, I personally love cold cake, unless (as previously mentioned) it's got butter in it... in which case, just warm it to room temperature before serving. But definitely run a test with your own recipe to see if it keeps.