I'm in Gilbert too, we just have a open air coop, all wire, and they do fine in the winter. If it was really rainy or windy and cold I could put a tarp up, but I never needed to last year. They always stayed dry and were warm enough. Mine just sleep closer together in the winter.I have a question. I have a coop, 4x4 not including the nest boxes, inside an enclosed run. I just have an always open door for them to go in and out of the coop the size of a large dog door. Is it ok to have that large opening come the cold winter nights? Will they still be able to keep warm enough? Do I need to do anything different? The opening opens towards a block wall fence about a foot away or so. It is protected because the whole coop is in the corner with a block wall on two sides. In the summer they sleep on top of the coop but I blocked that off so they would sleep inside where it is warmer now that winter is coming.