This year I picked up a set of Compression FLeece pants and jacket from Cabelas. HUGE difference.

Wool/Poly socks, 1200 gram Lacrosse boots, poly/cotton thermals, cotton camo shirt, Scentlock bibs & jacket, fleece neck gaiter. These things were good down to 40 degrees.

I added the compression fleece layer and I was still warm enough to sit still for 6 hours on stand Friday when the temperature started at 35 and went down to 25. I'd say that for the low 20s like that, insulated jacket and bibs would have been much more appropriate as by 5:30pm I had the first stages of hypothermia setting in (shivers and finger coordination starting). Who knew you'd need insulated clothing at 20 degrees?