We have a really small coop (less than the recommended 4 sq ft per bird) with a really large run (10 sq ft per bird) and a barn. We got our chickens this spring and they spend a tiny amount of time in the coop. Its insulated (as of yesterday--Yay!!!). The run is covered and has a wooden wall on the sides where the weather comes from (wind/snow), so they will have a pretty nice space there this winter. They will also have some time to spend in the barn, should they choose. My question is will they come out of their insulated coop in extremely cold weather (-20 to -40 F) and how much heat will they need and at what temperature? I have Buff Orps, Wyandottes, Barred Rocks and a couple Easter Egger crosses. Oh, and 2 unknown breeds, one of whom does not look to be as cold hardy. What do you use for heat? I do plan to start increasing their daytime light, in the morning, by just a few hours, hoping for 12 hours of light.