I've done it before but, of course, with caveats. 
I'm sure people here are tired of hearing how I store foods in the freezer, so I'll spare you. But I've gotten cakes that I didn't bake, but rather came frozen. I've let them thaw, then cut and froze some of the pieces, in the way that I store food in the freezer, and they've stayed perfectly pristine for as long as they've been in there.
I have some pieces of a very special cake I received for my birthday, just shy of 3 months ago, and they are in perfect condition. A week ago or less I had one piece and it was just as good as new.