Canada

That is a true statistic, yes. Without a ton of relevance to the discussion at hand unfortunately. Most of Scandinavia is coastal, and while cold compared to the rest of Europe, has quite mild winters compared to the northern Canadian interior. Additionally, popular in this context is about a 50% adoption rate by household, without much information (that I can find, at least) on distrobution; I suspect most of those are in southern and costal areas, and the (less populated) northern interior primarily relies on other heating methods.