How do I properly freeze a frosted cake?
You can generally freeze cakes, with our without icing, for a month without problems.  Beyond that, opinions vary...

How to wrap it depends on what type of cake and what type of icing.

For a cake covered in fondant:


wrap it in plastic wrap (multiple layers if you feel like it, by the time I make sure edges are overlapped I pretty much have two layers)
then wrap it in aluminum foil (I've never found a good explanation of why you need to do it, but it's what I learned to do...)


For buttercream:


freeze the iced cake first, then wrap carefully plastic wrap.
I've never managed to do this without messing up the icing at least a bit.  Work quickly, try not to touch the icing (heat from your hands will soften the icing), use lots of plastic wrap and let it be a bit looser.


In your case:  if "closer to Christmas" means "in a couple weeks" and if the icing is very nice, I wouldn't wrap it.  I'd get either a large enough container or a large plastic bowl that could be placed over the cake and sealed to the plate and just freeze it like that.