> One very small part of the arctic circle.
I'm not sure where you get that from. I suppose you mean that there are areas in Canada that are as cold, and have a larger population - but not, as far as I know, as far north:
https://en.wikipedia.org/wiki/Arctic_Circle#Human_habitation
"The largest communities north of the Arctic Circle are situated in Russia and Norway: Murmansk (population 307,257), Norilsk (175,365), Tromsø (71,295) and Vorkuta (70,548). Rovaniemi (61,329) in Finland is the largest settlement in the immediate vicinity of the Arctic Circle lying slightly south of the line.
In contrast, the largest North American community north of the Arctic Circle, Sisimiut (Greenland), has approximately 5,000 inhabitants. Of the Canadian and United States Arctic communities, Barrow, Alaska is the largest settlement with about 4,000 inhabitants."
Tromsø has a relatively mild climate (record cold temperature in winter is ~ -18C, "usual" coldest days of January and February are around -10C). The north of Finland is much colder in winter due to being away from the warm ocean currents, as is inland Norway.
(Source: I grew up in Tromsø, and worked for a while as a city guide before I moved south to Bergen)