Lowest low I've seen in my local area is somewhere around -17F with additional wind chill. Chungus and Dingus got a bit of rounded off comb tips their first winter, but it was largely because they were being derps and trying to pick ice out of their water bowl in single digit daytime...
I have 4 buff orpington hens from TSC that will be 3 years old in a couple months. Here are my fluffiest ladies, Chungus and Dingus, both around 6lbs:
It took them both some time to get to that shape; they were much leaner-looking for a long time.
And, uh...then there's Dimple. She's a tiny...