So far winter hasn't fazed them. Their water is often frozen by morning, but a gravity-waterer full of tap-hot water in the morning seems to stay liquid through the day.
Yesterday I stopped by the feed store and bought the last chick-feed these ladies will need. Next up: layer mash! I also got 50 lbs of scratch (~$15) & a heated dog bowl (~$25) in case it gets really cold. I'm not sure how the dog bowl will work, exactly. I'd envisioned setting the chicken waterer into the bowl, but the bowl is too small. And just setting water out in the dog bowl would result in fouled (fowled?) water in about 20 seconds flat. I guess we'll cross that bridge when we come to it.