Need a winter dress for a black tie wedding

Got invited to a black tie wedding and I'm kind of panicking cause I procrastinated it became very last minute. I've been to plenty of weddings but never black tie and definitely not in winter (I'm in cold location, it's not gonna get warmer yet according to the weather).

The wedding is in a historic venue, evening ceremony, so it's going to be cold getting there but presumably warm inside. I don't know if I lean into the winter aesthetic with darker colors and heavier fabrics or if I just find a classic gown and deal with the cold for 30 seconds. And where do you even find floor length gowns that don't cost $800 or look like prom?