You must be in Minnesota, because I have been dealing with the same windchill! I have zero bedding in the coop - I scrape the plywood floor under the roost every morning to keep it clean. (This time of year, I have to use an ice chipper - ha ha.) I have a wall mounted panel that I use only when it's going to be below zero. It will keep the area they sleep in at 3-6 degrees. Because of the -26 air temps we have had at our house (-45 windchill), I also installed a heat "lamp" that doesn't emit light. The exact name is Pinegreen Lighting 150Watt Black R20 E26 Ceramic Heat Lamp. It was about $5 and even at -26 degrees outside, both of these items kept the coop at 3-8 degrees. So no frostbite, no unneeded stress on the ladies, etc. I also worry about fires because of the horror stories I have heard, but I feel confident that these two items are as safe as can be hoped for. This winter, there are so many pictures posted of suffering chickens, that it breaks my heart. Good luck - February is supposed to be as bad or worse.
Going to deep clean the basement afterwards and be happy the girls survived the winter. They like to throw their shavings around and break boxes down there when I let them roam for a few minutes. But then I throw treats into the crates and they go inside and eat. I took a couple of the perches from the coop and put one each into each dog crate. They like that. 
It is definitely easier going downstairs in this frigid,life threatening weather than trying to make my way down a hill to their coop through 3 feet of snow plus snow drifts! With wind chills that make everything below freezing! More snow coming this weekend. 
