...which in the north only happens for a few hours a year...

I know the guy in the TC video used Chicago as an example but the "few hours a year" thing simply isn't true for many of us.

Where I live we had many days below -15f including a week where itpretty much stayed between -20 and -30 for nearly a week straight.

A Heat Pump will still work, even here, but you need to be careful about which one you purchase and how it handles cold weather.