My girls have their summer home, just a basic coop with wire along the top for ventilation, sitting on top of a large covered run, so that they can go into it whenever they want, and a trap door I can close at night. I have a poll barn that I can move the coop into if needed. What should I do for the winter? Leave the coop outside so that they can be out during the day, or is it safer to keep them in the poll barn all the time? We don't have any wind barriers and i'm not planning on heating the coop or the barn. I don't want them to freeze or get frost bite.