I live where the winter weather is fairly cold but not as cold as northern Wisconsin
. One thing, the daylight hours here are darn short at this time of year.
The indoor part of my coop has 2 side-by-side doors but no windows. One door is taken off thru much of the year and a screen replaces it. It is fairly tall and, with the pop door, provides good ventilation thru most of the year.
I don't feel that there is a good reason to have a window. That room is fully insulated - floor, walls and ceiling. It would, however, have no light during the coldest months, without electricity.
The purpose of the little 11-watt CFL bulb is not to provide any heat. The room is small so it provides enuf light. Heat is from the feed
. And yes, they do eat quite a bit more when it is real cold - up to about 1/3 more, I've noticed. Other than that increased intake, it's the
down coat that keeps a hen warm in my coop. I do have to get out there and get the eggs early on really cold days. There have been frozen eggs a few times.
Anyway, the light is on a timer. Years ago, I just left it on all the time because I felt that it was important for them to be able to get down and eat whenever they wanted to. In recent years, I've used a setting that is about
equal to the longest day of the year. I set the timer and turn the light on about the 1st of September, even before the screen comes out and I re-install the door.
Will your hens begin laying again soon? I think that depends on their age and how long they have been out of lay.
Steve