This is also our first winter with chickens! We’ve added loads of fresh straw, pushed snow against the coop & placed additional bales of straw surrounding it to help retain some heat. Just make sure there aren’t any major drafts and feed them cracked corn to help regulate their body heat. Consider a brooding plate if you’re really concerned. There is a Maine Backyard Chickens group on Facebook where a lot of people are discussing the care of their flock during this weekend’s extreme drop in temperature.