I had a thought about the snow men...what if you put plain snowmen on the door but had "cut outs" on magnets? Like paper dolls...different hats, different kinds of eyes, diffeent noses, different scarfs...other guests could change their clothes around. You could even do "costumes" Who would ever think of seeing a snowman with a pumpkin mask on?
My husband isn't crazy about our door being decorated...first cruise. But he might find some magnets on it or a post it note pad.