This will be our first winter with our 4 hens. We had chickens when I was growing up and I don't remember doing anything special for them, but those were the '70s....
We have a 4x8 coop with a 5 foot wall on the tall 8 foot side and a 4 foot wall on the short 8 foot side. Roosts are next to the window which I'm trying to figure out how to seal the gaps on....hardware cloth under the eaves on 4 inch high openings on both long walls. But I'm blocking the eaves with foam insulation on the west side since those are prevailing winds. The coop is on the south side of our garage so they'll have protection from the north winds as well.
As a Wyoming member said, we can often get down in to the -20 to -30 range for lows for a week or more...with "highs" staying below zero in some cases.
The only thing we didn't insulate on ours is the roof...do you think we'd be well served to cut some insulation to jam up in between the rafters? They can't reach it to peck at it up there...I'm thinking we should, hubby is resisting.
So far we've used deep pine shavings and it's staying very dry in there...we've only had a week or so below freezing at night. We do have a supplemental heater--a ceramic reptile heater screwed into a light bulb fixture hooked to a thermal block that will kick on at 25 I think and off at 35.
I'm not wrapping the run since it is on the south side of the building. We will be re-using some triple wall polycarbonate to block the wind under the run (there's about a foot or so of space under there, reinforced with hardware cloth) on the west and south side. We'll just tack it into place so we can pull it off in the spring. That will give them a "greenhouse" type Sunroom in the daytime under the coop.
I have two big bales of straw in the garage (to stay dry) to parcel out to them over time--keep their toes out of the snow and such--and will get them some alfalfa hay to do the same (and for something different to peck at).
I am assuming that they'll hang out inside the coop if the weather outside is too cold and windy...