An update on my frostbite issue; we've been getting a little bit worse on the combs.
The ventilation is good- I think it's the extreme low temps. So far the toes and feet are okay, which is the really bad place to get frostbite. I am terrified of frostbite on feet or toes.
The leghorns seem to be suffering the most. I regularly see them shiver and they both seem dirtier than they should be- and slightly skinny- I may weigh them to keep a record of any weight loss.
Temps are regularly dipping to around -20 at night. Some days it doesn't get much above that. We've had a couple -30 days. I have been keeping the birds in the coop during the day as it typically remains around 0 F with strong winds, but yesterday, they forced the pop door open and let themselves out, then it seems the wind blew the door shut and they locked themselves out of the coop until I got home from work. Three eggs laid on the ice and frozen/cracked, which I then cooked and fed back to them. (They were super-frozen! It was like peeling a hard boiled egg)
When I opened the door back up, all eight went right back inside the coop.
My EE went right into the nest box and layed an egg. She seems to handle the cold the best out of any of them.
She is the only pea-combed bird I have, and also the only without any frostbite at all. If I'm planning for another super-cold winter, I'm seriously considering getting only pea-combed birds in the future, even though I adore my leghorns.