Then, no one can drink snow. So you will have to get real water, in restricted quantity, and be careful with it.
Sorry, but you're kinda wrong here; during my time of serving the Norwegian army, we had to fill up our canteen with snow after drinking some of the water, then keep the canteen wrapped inside a long sock which hang round our neck. This made the warmth from our chest to melt the snow, so we could drink it as water just 15-20 minutes later. For us, this was vital to survival, as we started out with just 0,7 liters, but needed somewhere around 2-4 liters of water every day when out in the field during the winter season.
I think that if this could be modded, it would be even more immersive than just having to fill up water from some flowing water stream (yes, it HAS to be a flowing one, because if the water is still, there's a *hitload of bacterias, animal feces, and generally a lot of crap in the water. But in the snow there's a minimal amount of bacterias, and rarely worms (I don't know what the correct word is in english) if you just know what snow you can use.)
Edit:
The one thing I would really like to see in a mod is as some here say; to survive the environment. I have no idea right now as to how this would be done, but as proven in earlier games, especially TES games, there's a lot of inventive minds, and a lot of smart modders
