Welcome! This is a wonderful site and has helped me numerous times! Here in Texas it's the heat we have to deal with, but I think you sound like you've got the cold factor covered. Their feathers will keep their bodies warm. I try to keep my coop at least 40 degrees--that's as good as the little heater will do--and has managed even in 9 degree winter days. It's just a little ceramic heater we sometimes carry with us camping and works great in our rv, so would do great in the coop--which is just an insulated storage building. What to watch on your chickens is their feet and combs freezing and doing damage. Just keep the coop 40 degrees and the chickens will be fine. One thing I love is my inexpensive baby monitor I use to make sure nothing is amiss at night with my girls. If they get alarmed because of a critter in the coop or fire, I will hear their squawks and can respond. You might like that as well, just remember to turn it down until you can barely hear them snoring. That way you can sleep OK but be able to hear if they get excited. Their normal night noises will be too soft to bother you. : )