Tali is in Mass Effect.
And considering the current status of Skyrim mods, chances are this is a map+graphic mod with a couple quests. Doing more would require a talented hacker or someone from the inside, it's usually the latter. No tools are currently released to change the skeleton of the models and you can only replace animations with an other. Though you could probably change the race to an identical custom race with different animations to play a new animation, then switch back, but this'll require hard-coding. Any ways, the point is; worrying about the cold isn't really an issue.
And just a side note, if someone were to work on an expansive mod that includes the map, the races (ex: Rio isn't just some costume) with animations for the extra parts, and include some kind sex mod like lovers, chances are the mod is going to become a lot more popular than the original HTH. Just saying.