I didn't see it mentioned yet, so I'll throw in my hat. You say you don't use a bladder because the hose freezes. In the winter I use a cycling hydration pack that I wear backwards under my jacket. It has a short hose that I keep tucked in at my neck. I've never had it freeze, even when the temperature was -10F. I also don't have to open my jacket for a drink which might be a problem with a bota bag (wineskin).

I heat the water until it's hot to the touch before putting it in the bladder. Then it helps keep me warm while I'm relatively inactive in camp. If you try this, you must at least warm the water to body temperature. Cold water under your jacket is going to be uncomfortable. At worst it could lead to hypothermia.