Years ago someone wrote that a pound on your foot is like 5 pounds on your back I believe it. I wear Merrel boots. Light and comfortable. Even at 7000 ft. here in central NM in December I wear uninsulated boots. In Colorado, if there is snow, you'll want some insulation, and lightweight gaiters. I've never used more than 400 gm. Thinsulate. What I've found is that if you have plenty of toe room, your toes don't get cold. You can order from Merrel directly and get just the width you need. I always take two pairs of boots on a hunt.