It got down to 12* here last night. It's 18* now. I keep my furnace set at 63* at night and 67* during the day.
Am I cold? At night no, I have an electric mattress pad that I run on the lowest setting. During the day I freeze. I have a foot heater that uses very little energy (less than a lightbulb) to keep my feet warm while I work and I dress in layers. Still cold. Part of that is just me. I am always cold. I should move to the tropics.
How did everyones chickens do? I've been ready you should line the coop with hay bales and spread a nice thick layer on the floor to insulate the coop. Makes sense to me. Might be a pain to keep moving it in and out due to the bi-polar weather, but worth it in my mind.