Cake with ganache on top going to the freezer

You may absolutely freeze chocolate ganache and most other chocolate preparations. It should keep for up to a year without any noticeable change in quality.

Try to get a tight seal so it doesn't pick up other freezer odours. Use a small freezer bag if you can, and maybe put that in a hard sealable container as well. The freezing itself won't hurt the ganache at all but if it catches a whiff of those tuna casserole leftovers then you won't want to use it!

I've actually found a combination of both aluminum foil and clingfilm to give the best protection. The foil is most effective at preventing freezer burn, but does nothing to isolate odors.

Since the freezer is so cold, you don't ordinarily smell much when you stick your head in there, but that doesn't mean that the odors don't spread about, and you'll notice it only once you thaw your chicken (or other food item). That's why I like to wrap my food in clingfilm as well, but more pertinent to your question, the foil is what you want to prevent freezer burn.