I live in Maryland and the first townhouse I owned, in the late 80s to early 90s, had a heat pump. It included an auxiliary electric heater for days that it got really cold. I don't remember it coming on all that often. (There was a light on the thermostat to indicate when it was on.) My current townhouse has a gas furnace. I plan to move soon into a single level home, more appropriate for an old greybeard, and I'll have to evaluate then if I want to switch to a heat pump, if the house doesn't have one already.