I don't recall my chickens ever not ranging because of the cold, but if you're free ranging your chickens, they should always have access to their coop anyway. That way they can choose to either go out or stay in.
In NY it's a lot colder, so you'd have to keep an eye on them. If they're huddled together or shivering (which I've never seen do), then you'll have to something for them like keep a heat lamp out.
My first year having chickens, I put a heat lamp in the henhouse for them when it dropped into the teens and twenties, especially overnight. I don't do that anymore, though I do check on them. If I look in the henhouse and see that they're somewhat spread out and comfortable and roosting, then I don't worry. It's seldom below freezing here in the daytime, but overnight it can dip into the 20s, 10s and sometimes in the single digits.
It dropped into the single digits overnight a few times and I didn't see anyone uncomfortable, nor did I provide a heat lamp.
Though sometimes when it's that cold, I bring them hot food, like oatmeal or grits, or whey or something they like