Perhaps you're right, Grits. But what I've seen of Skyrim's environment suggests taiga and tundra - i.e. a more Siberian climate rather than a Northern Ireland/Scottish clime. I could be wrong, and I will naturally defer to those who actually live in such places.
That's not to say the dog (Ulfe it is!) can't survive there - she just needs a lot of meat and a very rich owner to maintain her energy level and stay warm! As for the sleeveless thingamajig, who's to say it isn't enchanted with Resist Frost? Like some of those HH-cup flimsy metal bras we keep seeing in mods

aren't charmed with Feather?