you're not making the point you think you are. The average January temperature in most of Norway is about 10 C higher than in most of Yukon and Alaska. Norway just isn't that cold.
That said, heat pumps absolutely do work in -20 C. I would know because i have two at home and one in the car. All three worked just fine at -25 C this past winter.
That said, heat pumps absolutely do work in -20 C. I would know because i have two at home and one in the car. All three worked just fine at -25 C this past winter.