Cold Weather Sleeping Bags
For cold weather camping, even in quite extreme conditions, you don’t need to spend the big bucks on the latest hi-tech sleeping bag. I have slept outside, under the stars--no tent, no fire, no shelter--at minus 30 degrees F. in two $20 sleeping bags, one stuffed inside the other.
Stay away from cloth bags--cotton retains moisture, which is then difficult to thaw and dry. Bags with a nylon shell and lining basically shed water and are much easier to dry if they do get damp. In the morning you can open them up, and, after a short time, shake most of the frozen moisture off.
You do get what you pay for, though, and a high-quality sleeping bag is worth the investment if you are going to get some use out of it. Here is a great one: http://www.rei.com/product/795779
Whichever course you take, try your bag out in the back yard before your trip--no matter how much you’ve spent. I’ve been deep in the bush on bitterly cold nights with folks who really, really wish they would have done that.