Yeah, it's a crude metric for sure, but we have to make sure we're making a good comparison before claiming "If there was going to be a problem, there would alr

Yeah, it's a crude metric for sure, but we have to make sure we're making a good comparison before claiming "If there was going to be a problem, there would already have been a problem." Notably, some Googling indicates that heat pumps aren't effective below -13F which can be the high temperature in Iowa (never mind colder states) for week on end. Are heat pumps common in parts of Scandinavia that get this cold (or colder)?