Wasn't Red Mountain supposed to be bigger?
Regardless, I hope it's huge. Big enough that reaching the top is an undertaking. Hopefully the trip will be dangerous, perhaps a quest to reach the top and bring back some rare alchemical ingredient or something.
I wouldn't mind some Udyrfrykt creature in it. The Udyrfrykt and Uderfrykt Matron are both taken...maybe the Patron...or perhaps just nothing. I don't know. Some kind of abominable snow creature. Perhaps something like the Rieklings from Bloodmoon.
I think Bethesda's technology and engine att the time Morrowind was made couldn't handle a huuuuge mountain, but yeah red mountain and throat of the world is the biggest mountains in Tamriel. I too hope there are unique monsters and creatures high up in the mountain, only high lvl characters should be able to climb the whole thing and survive, atleast thats my thought. Mount everest is not a place everybody can climb