I like Meindl Perfekt Hunters. These have 400 grams of thinsulate. They do NOT make my feet hot and sweaty, and I have worn them in 70 degree days hunting deer in Oklahoma. I will say that when it is cold my feet did get cold. I got cold toes on a goose hunt this past weekend when the temperature was just about freezing (32 F), and that really isn't very cold. They provided very good support and traction hiking around high country in Colorado hunting elk this past October, including carrying a heavy backpack back into camp. These boots broke in very quickly, also.

For the application you are discussing, I'm not sure "light" is what you need. For mountain hunting, in my opinion, you need a fairly heavy boot to provide excellent support when walking and climbing rocky trails or bushwacking off trail.