Thanks for the correction. That's my point precisely. Given the CS, Vvardenfell is "officially" too small It's geographically too small for it's climate and geology.
New York City is rather small in land area. Blizzards hit NYC not Flatbush.
I won't argue that it's a small place. With MGE, it feels like you can walk the length of it in a day or so. (I have)
However, that said, you can see dramatic changes in climate as a function of elevation. The Dixie national forest in Utah is a perfect example. In the summer, if you drive in from the East, you can be in the middle of a hot, arid desert. In about 10 minutes, as you climb in elevation, you find yourself first in a pine forest, and then a birch forest. Birch can't survive temperatures much above 65-70 degrees for extended periods, so that should tell you something there. (BTW - Dixie is an awesome place to visit anyway - well worth the trip)
The only part of Morrowind that is hard to buy is Solstheim. It is far too close to Vvardenfell, and too low in elevation, to have snow anywhere but the northern-most region - and even then, light snow; not a glacier. The rest of the island is at least somewhat believable - especially if you consider the Ascadian Isles is really a lightly forested Savannah.