Oh, I just remembered something else.
After the summer fete thingy, I had quite a few cupcakes left over. So when I got home, I put them in 4 hole plastic pod type thingies and bunged them in the freezer. When my sons went to friends, I'd take a pack out for them to take with. Or I'd take some out if I had a friend over for a cuppa, etc....
... they froze and defrosted beautifully. Some had normal buttercream and some had IMBC.