I don't think the idea is stupid, but I am siding w/ Diabolical on this. Think of it this way: Now your anniversary will be on Christmas eve. Fast fwd to when you have kids and she's running around like a mad woman having to make Christmas "happen" for the whole family and there's no time to feel special and celebrate your anniversary. Just saying. Holiday anniversaries (like Valentine's day, Christmas, etc) and Holiday weddings are problematic.
I know your revved up to do it, but maybe wait until Jan? Ilike your idea, shows creativity.