Not saying they do, but hypothetically they could (and some survivalists and bushmen still do) would make storage areas raised off the ground which would preserve food a lot longer, keeping it out of the sun and away from animals, it's a cold climate already, there's no need for a fridge. Even in the less snowy parts of the land, the ground is probably still frost to a certain depth.
Through the documentary and book "Alone in the wilderness" I learned some people would even make underground "refrigerators".
http://www.empowernetwork.com/Benstarner1/blog/dick-proenneke-survivalist-extraordinaire/
"Their are a few things I find compelling about his story, one of which is that he built most of what he needed to survive himself, from off the land he lived upon. He built his cabin, he made wooden bowls and utensils and even constructed an underground “refrigerator” that kept his food cold even during the heat of summer."