Hi, Mohawk,
I've just completed a traditional bedroll after much research into the pioneers of Western Canada. It consists of a canvas outer, two Hudson's bay 3 1/2 point blankets and a liner of Canton Flannel. According to contemporary accounts, it's good down to about 12F (-10C). It's heavy and bulky, but has a lot of advantages over modern lightweight stuff, mainly that you don't have to carry all of it all of the time, and the parts can be used for other purposes.
A single blanket can be worn as a match coat when on the move in cold weather, and used the right way, an emergency shelter can be made quickly.
The HB blanket has stood the test of time, having been constantly in production since 1780, without any substantial changes in manufacture. There are plenty of them in use that are over 50 years old, and if cared for properly they will last for a very long time.
For ground insulation, the first choice was buffalo hide, followed by bear skin and then wolf skin. As I can't afford any of the above, I use a double sheepskin rug, which works perfectly well.
I hope this information is useful, and as an aside, I'm replacing all my modern kit with old-fashioned stuff, and I've found that weight-wise, I'm actually carrying less, as the old kit has multiple uses.