Although I’m a fan of WM B/C I’ve used an overstuffed 20 F. Â WM Megalite since 2012, I like the Polar Ranger for its many features but especially for the DWR treated down. That is important in winter! My LL Bean -20 down mummy also has DWR treated down nd it works.
BTW, check out my “SYNTHETIC TOP LAYER” thread here in Winter Hiking for more info on winter sleeping WITHOUT frost buildup in yer bag.
->->Also see the YouTube videos by a Canadian hiker who uses the Polar Ranger with a synthetic quilt “topper”. Search for Canadian Rockies winter camping. The guy hs some good advice and is very experienced.