Waterproof and warmth aren't usually a useful thing to mix. Because when you really need it to be water-proof you likely don't care that much for the insulation

Waterproof and warmth aren't usually a useful thing to mix. Because when you really need it to be water-proof you likely don't care that much for the insulation (although you do care about wind-resistance), where as when it's really cold - it really makes no difference whether it's waterproof or not. I tend to get a light non-insulated (but wind-resistant) shell and a light down-jacket - which in my experience works under all but the most extreme conditions.