Yes... This morning it was 9F. NNW of 10mph , My birds are in and uninsulated well ventilated coop and they were fine. They even came out side and had their morning meal worms. Because I feed 18% protein, scratch, and mealworms I don't consider meal worms a treat. At around 50% protein I consider them part of their daily diet. And scratch also. I up the scratch in the winter time because it is high in calories and helps them keep warm. I lower the amount in summer. It was hot and humid here in Maine last summer. We were in a drought many dry wells.
If anyone believes their chickens are cold just reach under a wing or under a nesting bird. Warm under the wind warmer under the nesting bird. They need to be warm to incubate eggs. Chickens run around 106F. Two coats One down one feathers they puff up to trap warm air from their bodies. When someone asks me if I heat my coop I say, "I have 12 mini heaters in there." And then I start with the names. LOL. If you heat they may lose their down coat and when you have a prolonged lapse in electricity then they are at risk of being too cold. Let them be chickens. Good luck