This is really striking - I really like it! Is the Frozen Realm of Ryntr a high plateau? That would explain the frozenness, but it's not obvious from this map style. (It reminds me in that respect of Tolkien's Dorthonion.) Or perhaps it's cold because the mountains cut off the prevailing winds from the west - though while that would lead to colder winters, the summers would be warmer. Also the lake at the bottom left seems to have a river running into and out of it a couple of times on the western side, which looks odd!