So we got a full-sized school bus this year for our new coop. The front portion is closed off for storage. All the windows in the bus are open 1/3 of the way for ventilation. They have a big run - approximately 70 x 50 feet with lots of tree coverage. Our winters get to -38 (sometimes -40) Celsius for over a week at a time. I don't heat the coop. I just have two large heated bowls. - Their feed is about 19% protein. Would you suggest anything else to feed on cold days? Last year we did black oil sunflower seeds. - Do you think my ventilation will be OK? - Their entrance has a ramp up to one of the windows. I am waiting to see if this will be an issue in the winter.