I am in Montana, but spent three years in Anchorage, AK. Yep, I was in the Army stationed there a while back. I know the answer to how to keep your chickens warm in the winter as we have cold winters in Montana too. You suspend a single 65-70 watt light bulb in the coop, in the center of the room where it is away from the walls, nesting materials etc,. If you leave it on it will maintain a comfy temperature as long as your coop in not too breezy. Otherwise you can put a small heater with a thermostat under the coop, but out of reach of the chickens and set it at a reasonable temp. It will kick on and keep them toasty warm. Or you keep them in a heated barn or basement.