OK, I decided to try it without a coop, just the covered pen with the door open for my free-range girls. Last night, I had all 8, this morning just before sunrise the temp was down to 23 F. I still have all 8 girls, and as of 8:30 am, have already collected 3 eggs laid this am. As the weather has gotten colder, I have increased their scratch, to give them more carbs to burn for heat, and I have sheltered places all around my backyard, so that no matter which way the wind blows, they can get out of it...and they HAVE found all the shelters. I also had plentiful weeds which went to seed, and they love those. They are enthusiastic over the scratch at first, then go back for the weed seeds without eating even half the scratch. They occassionally go for the crumbles for a few pecks, then back to the weeds. I'm just letting them self-regulate their eating habits, it seems like nature leads them to what they need most. I'm still getting 6-7 eggs a day. There are so much of the crumbles left over in the feeder that I won't be giving them any more tonight. Or I'll just fill it up and let it be for a week or more. It would seem to me that as long as they are protected from the wind and have perches a little above the ground they are doing just fine. Time will tell, with the Dec and Jan cold with nights around 10 degrees colder and a couple of cold spikes down into the single digits, but it seems to me that any weather that pigeons can survive, a well-fed chook should be able to survive.