I've read lots and lots of the posts and suggestions that seem to be weighted against adding heat for chickens, even in their coops. I'm comfortable with that. I have made the area near the coop somewhat protected from wind and snow (using tarps, wood, plastic and the enormous Douglas firs overhead). I use a couple of methods to keep their water liquid. What I am wondering is that my girls have a good, well-ventilated, dry coop, but they do not have a specific run. They roam my large backyard freely. And yet, even during extended periods of temps in the teens, with icy winds and some snow, they insist on wandering around the yard and huddling here and there. I worry about frostbite and other issues from the cold. Should I make an effort to enclose them in the more-protected area, or allow them to choose for themselves where they want to be? Thanks!