Good advice, after daytime highs of 15 for 3 days straight, we bailed this year. Even with the stove pumping, we couldn't thaw our water jugs. The nights were just plain brutal.
It depends on the weather... Generally, if temps are below 10-15 F, you'll need a wood stove/tipi. It's some work cutting wood and feeding the fire, but really keeps the morale up when hunting the cold temps, and the ability to dry out. I'd say 15 is the limit with cold camping, unless you want to sleep with a cold water bladder.
Another factor to consider is water sources/filters freezing. Take tabs and know where a spring comes out of the ground