my crazy hens don't like insulated coop and chose an open horse stall still have a problem when it gets to below negative 20 and looking for other solutions for the watering as below negative 20 haven't had much luck with anything the metal waterer with heating base didn't work was a waste of money as it says only works to -20 and first day below that it was trash.
What we did was lined the stall walls with hay bales, put extra hay down on the rubber floor and in addition to the regular feed take them a bowl of oatmeal with about 1/2 tsp of garlic and another of cayanne pepper in the evening and morning, helps em keep warm from the inside besides huddling up. as they aren't babied they look funny but they get in extra down like cattle and horses do undercoats. We had chickens with down poking out through the feathers but they survived Idaho winter but had to take water out 4 sometimes 5 times a day for them. they do have a smaller stock heater for plastic pales, so going to go get one of those and the pale that goes with that and see if that works as it is designed for inside a plastic pale.
our flock last year was 2 roosters and 10 hens
this year our flock is 2 roosters and 17 hens as they hatched out in the spring and we kept some of them. the rooters always having to be up top when they are enclosed lost their combs last year so won't be a problem this year, but we had over a week we were -20 to -30 before the windchill, the hens stayed on perch or went into a cave on floor surrounded by hay bales or the brooding box that is in between hay bales and didn't have any issues we didn't loose any chickens or roosters due to the extreme cold
our flock make up is
BR
leghorn
BO
BS
amerecuana
and now a bunch of barnyard mixes.