These are the best cold weather pants I've ever owned. As with all loft insulation (at least in my experience anyway), they're usable in a wide range of temperatures. I've hunted them in temperatures from the low 50's down to the teens and they have been comfortable. The lack of bulk is extremely nice when you need to put waders on over the top. It allows me the flexibility to wear non-insulated breathable waders in very cold water and not feel a thing. The only "issue" I had was with sizing. I'm 6'2" with a 34-35" waist, so I should be wearing a Large Regular or Large Tall. I tried on the Large and they were WAY too big in the waist. Luckily I found a Medium Tall and although the size chart says that shouldn't work for me, they fit absolutely perfectly. There is room for a thick base-layer underneath, but they aren't bulky at all. Sitka's Customer Service is awesome, by the way. I ripped these pants the very first time I wore them. I am fairly certain that I snagged them on something (it was dark so I didn't see it, only heard it) and told Customer Service that. She said "Nope, that's not supposed to happen" and took care of me without any debate. A patch kit was sent to get me through the season and she offered to repair them once the season is over and I can spare the pants. (The patch kit is so robust that I don't think a repair will even be needed.)

I have worn these Boreal Bib Pants for 3 days now in below freezing temps with 20mph wind while hunting waterfowl. All I layered with was just the Traverse bottoms under them. These are extremely warm and comfortable. No bulk to them at all. I did try them on with the Traverse bottoms and the Grinder Pant and they still fit great if you need multiple layers on. By far the best bib pant. As a waterfowl guide I put gear through the ringer and these look like they will hold up for years of use.