We also have cows on my fiance's farm that do not have any type of shelter to live in or go under and they do fine all winter long. The only fatalities that she has ever had was occasionally with a new born calf. I personally don't think chickens need any type of hi tech shelter to survive. They do have feathers for insulation. Back when I was a kid and we had chickens, we never insulated the coops and never had a chicken die of cold. Plus these coops were not the best built and were drafty. I think a lot of people here get overly concerned about the winter thing because they consider their chickens pets and want to treat them like a cat or dog and keep them somewhere warm.
Wayne
Wayne