We had two weeks recently where it never got over 22 -- and looking at your state, we're not far apart geographically. My method might not work much farther north, or in some of the more interesting sections of the Great Plains, but it might work for you.
I use a black hog bucket in the winter; it'll keep open enough for drinks all day unless we don't break into the teens -- and if it's clear and cold, with the sun out, it'll stay open to an even colder temp due to its color. On the rare occasions where it does ice over, I just break it out when I get home from work and give the girls fresh before bed. They drink up and go to sleep and everyone's just fine. I've never been mobbed for water, so they're clearly getting their fill. They don't drink at night, so I don't worry about keeping it open then.
I am careful to get their actual waterer inside and dried out and use the hog bucket instead before we hit freezing temps -- that's not so much for the chickens' sake as it is to keep from having to buy a new waterer every year. Freeze-thaw cycles are HARD on those things (as evidenced by the number of rabbit bottles we go through every winter), but the hog buckets will take repeated freezing and abuse.