Spent the last hour reading Vapor Barrier (VB) threads as dp hammocks and quilts use VB technology. ( small, light, not expensive, and easy to dry if necessary using synthetic insulation)
FYI: I've read often, the Mt. Everest climbers' down sleeping bags easily double in weight with moisture and ice, even tho they attempt to sun dry them out, if possible. It seems to me, at some point, synthetic insulation would be better than down?
Below is what works of me with Vapor Barrier technology ...
Synthetic long underwear and socks (don't like the VB feel against my skin)
Sleeping in pertinent clothes for temperature (NO cotton)
dp hammock that is nearly water proof (vapor barrier and can be used as rain gear)
dp top and under synthetic quilts with VB technology that is "next" to one's body, the outer fabric is DWR. (Allows for smaller, lighter gear in low temperatures)
I do not "hang" if temperatures are single digits F predicted.
I hope this reply may be of help to some ...