More like winters that get down to 0° Celcius/32°F at night. Here in the Seattle area, if it gets close to freezing, the “strip heater” (supplemental resistive electric heating, like an electric furnace) kicks on. When I lived in Indiana, which most definitely has 0°F winters, the few that bought heat pumps hated them because the “heat pump” part didn’t get used for a few months in the winter while the real furnace did the work. Granted, that was 25 years ago, but physics hasn’t changed much: how much heat are you going to suck out of 0°F air?
The heat pump does a much better job of cooling the house in the summer in comparison to a gas furnace, though.
How does that look for Geothermal heatpump, where you drill down a borehole and 'steal' heat from the ground? The temperature of the ground does not vary much seasonally.
Geothermal heat pumps (aka ground sourced heat pumps) have a high initial capital cost. Their suitability also depends on the local dirt as much as the local climate. You need good enough ground moisture levels to have a high enough thermal conductivity. Otherwise the cost of the hole becomes prohibitive.
Well, speaking of Indiana, I worked at a church in IN that used the type of geothermal you describe. Kept the church warm all of the two or three winters I was there. IIRC (and I probably don't from 25 years ago), the ground temp was around 54F at the depth it was pulling from.
The heat pump does a much better job of cooling the house in the summer in comparison to a gas furnace, though.