We're not doing too badly, even though the temps have gotten to -20-30 during some nights. We're using the "deep litter" method and I think that's helping to keep the coop warmer, and we have two 250-watt heat lamps over the roosts. We have 24 chickens - 23 pullets, 1 roo in a 10X12 coop and they have plenty of room but it's small enough to conserve warmth. Their unheated, galvanized waterer has only had frozen water a few times this winter. Sometimes it has some ice but it isn't frozen over. We change the water once a day. I've been putting vet rx in their water every other day or so, too. They're laying pretty well (just started laying in October/November) - yesterday we collected 22 eggs. Seem pretty healthy, considering. We don't let them out every day, though. And when we do, most of them don't want to go outside because we don't cover their run and it's snowy. They don't seem to know what to do with it.