Ask your cousin in Winnepeg if there are any other birds that live there year round, like ravens or owls or chickadees. If they can make it, the chickens can make it too; at least the chickens won't have to hunt for their food!
It has gotten that cold here too, but never for weeks at a time. -25 for weeks at a time, yes, but those minus 50 and below cold snaps are pretty rare and fairly short.
It depends on how long it stays at those temps... if it's longer than a day or so, then yeah, add a little heat.
We dropped from fairly "pleasant" freezing temps to -35F overnight... and stayed there for over 2 weeks straight. That wore on me more than it did the chickens. They stayed in their coop for the most part, and didn't do a whole lot. But with proper housing and protection from the elements, they should do just fine at those temps.
I would not ad heat at -60, but I would drape blankets so their roost area was smaller with a gap at the ground and a gap at the ceiling. Even a shower curtain would work, but blankets would not conduct as much heat.
But again, there are wild fowl that survive there, so chickens can too.
I don't know how you guy do it! I think anything below 50' F (that would be on the plus side of zero) is inhumanly cold. I find our winters unbearable (central OK) we usually have 2 weeks or so of snow on the ground, and probably about that many days where our high never makes it above freezing and that is waaaaaaaaaaaay to many for me.
When I go to work in the summer here not uncommon to be above 100' I bring a coat b/c other people use the air conditioners to the point I lose feeling in my fingers and they turn blue.
Every climate has it's own trials and it's own blessings. For me, I'd take this over a hot climate any day. The winters are beautiful in ways I never imagined when I lived in Michigan or San Diego. Being able to see Mt. McKinley from my house, 150 miles away through clear air, northern lights, ice on the rivers an iridescent blue, wild birds with their feathers puffed out till they look like tribbles with beaks, these are priceless.
Having daylight all night long in the mid summer, and glorious autumns where every snow free day is a blessing, and makes you appreciate the summers and the seasons, the uniqueness and the comraderie, it's all wonderful.
Less laws... that's nice too. Not that I'd want to do anything naughty, but I've got a two acre lot and no one cares what I do with it. It's just my little slice of heaven.
I can't take off enough layers to stay cool when the temp hits 90 degrees!!!
I had to change a flat on my car in the hospital parking lot at 20 below. I did the deed while humming happy songs because I had the right winter gear to stay comfy, I had a nice hospital lobby to warm up in if needed, and I still had the physical health and strength to do the chore. Of course, people walking by thought I was a nut case....