>>1899482>a pad to keep you from the groundSnow and ice can only get so cold, but the ground can get colder. you don't want to be on or near the exposed ground if you can avoid it.
Work your way up to winter over the fall OP, you'll find your threshold. remember that most sleeping bag ratings are pretty optimistic, so if your bag is rated to -9c, figure that you will be shivering in -3 or -5c and downright miserable at -9.
I don't know about Colorado, but full Canadian winter of -40 you could die if you are not prepared. exposed skin can freeze in no time and it sucks. I have had to work outside in -20, not the most fun, but never spent more than 2 hours in -40 with nothing exposed but my eyes and they hurt when I got inside and my eyelashes were frozen with ice balls from my tears.
