Thank you Pat, for giving information on the heat tape idea and the various reasons that's a problem. I, too, would suggest a 2x4 for a roost.
I'm one of the people that has a heat lamp available to be chained to the rafters, for the bitterest nights. We don't use it all winter and we don't use it during the day. We use it for bitter cold spells, that come on suddenly. It's reserved for nights where the temperature would suddenly jump from a low of say, -10 one night, to -30 the next. That's pretty cold and a pretty big jump. In a big coop, the heat lamp just buffers the cold, it doesn't make it toasty warm. We are lightly stocked.
Do we have to use the heat lamp? No. It's just our choice. We could also enclose the roosts, to keep in more body heat while they are roosting. DH didn't want to do that. We could also do nothing. Of course, then I'd see them hunched up, looking cold on the coop cam and I'd feel bad.
I can see where it's much more of a management problem for people that have chosen chicken breeds with larger combs and have roosters, too, in the bitterly cold areas.
We use a combination of snow blowing, shoveling and a run cover to deal with snow. DH snow blows paths for the dogs and chickens. I do a little touch-up shoveling around the run gate or in the uncovered portion of the run. Next to the coop, the run is covered, so I don't have to dig the chickens out in the morning anymore!
We had over 100" of snow last winter, so had to do a little more snow management than usual.