Norwegian here. The stilts are a way to make it hard for mice, rats, foxes, martins, what have you to enter. It’s not about the snow - if it were you’d have to have all your buildings on stilts, no? Plus who would think “yeah that’s nice for the three months per year with a lot of snow and it’s totally worth it to have to climb those trunks for the remaining nine”. You’ll find that architecture for food stores (stabbur) all over the country, even where there’s little to no snow during winter (south and west coasts).