Winter coops

[GoldenGirlsx4]

I need ideas on how to heat a chicken coop, housing 4 hens, in North Dakota Winters. We are the Siberia of the Northern Plains. Wind chills can get to -75F and normal temps as low as -50F. The coop we have is 8'Wx6'H16'L. I'm on SSDI and $$$ is ever so limited. I'm nearly 66 and do all outside chores myself. So I need economical advice.

 

[azygous]

I have two coops. I heat the larger one with an electric oil-filled heater to keep the coop just above freezing.

My other coop houses the remaining seven hens and is smaller. I use a Cozy flat wall electric coop heater https://www.amazon.com/dp/B01LX9K1JI/?tag=backy-20 to keep the coop just above freezing. It's inexpensive to buy and economical to run. The beauty of it is it takes up zero space and I positioned it just behind the perch so the hens can roost in front of it for extra warmth if they choose, or roost away from it if the night becomes warmer during the night.

 

[Maiahr]

I just ordered cheap ceramic heating bulbs, 75W and a 100W. They haven't arrived yet, they were something like 2$ each, don't remember exactly.
https://m.aliexpress.com/item/40001...d=2661amp-0VLfBf1P6bQej490dwuTew1573069977501