Ideas on what to wear for our renewal of vows ceremony in Central park in December?

Me and my husband are renewing our vows in Central park towards the end of December and I really have my heart set on wearing a tea length 50's style strapless dress, with a large fur shawl to wrap around my top half. But I have a feeling I will still be cold, but think I might be able to handle it?!!? Would really appreciate any other fashionable suggestions that would fit in with the look I'm going for, or just any ideas on what to wear in general!! Thanks