Freezing feet and zero regrets — what actually works for winter weddings?

My sister just got engaged and immediately said "December wedding" like it was nothing lol. I panicked a little honestly. We live somewhere that gets properly cold and I keep thinking about frozen guests and ruined photos. She's set on it though so now I'm the one googling at 2am. Anyone been to or planned a winter wedding that actually pulled it off beautifully? Tips, tricks, real talk welcome. I'm also having a wedding in the winter, share your esperience.