A sign saying Labrador to me is less proof to me than a body of pictures documenting the culture; and I don't necessarily mean artistic or traditional culture, it could be streets, houses, road-signs, shops, infrastructure, etc. that have features that rule out it being anywhere else, that's what's lacking. If Tristan da Chunha is a bad example, you could try Greenland (only double the population of Labrador but sparser), which is even colder.