I'm a bit naive as to how large countries like Canada monitor their space, but is it possible there are unknown long-term (multi generational) "settlements" separate and unknown to the rest of the world still out in the middle of nowhere in Canada? Feels like a good subject for a novel :-)
I've driven and hiked around the Canadian bush quite a bit. It is hard to explain how incredibly large the area is in terms that makes sense if you haven't been there. It isn't uncommon to spend days without seeing another person. It's so quiet the only sounds you hear are the wind (if there is wind), animals and your own heartbeat. It's also beautiful and brutal at the same time, a single mistake and you're done for…
There's a lot of surface that are covered by glaciers or forest and not visible from the sky.