I know the 8x8 rule isn't exactly accurate. While the extra water doesn't hurt, it really isn't a necessity most of the time because we get water from foods, water-based beverages, etc.
But I am going to school in Helena, MT, and typically the winters are very cold and very dry. I often drink as much water and liquid as I can (and I rarely take caffeine), but I still find I am thirsty. I have a small stomach, and upping water intake usually makes me feel uncomfortable or I can't eat enough- but just how much water do you need in cold, dry, and high climates, compared to moderates?