I was given an Army sleeping bag system from my father-in-law a few years back. The sleeping bags I have used often fully aware of the weight penalty. (Remember they were the right price) The system included a bivouac bag… I never had much interest in using it, as it would put me too close to the ground. However, it is of high quality make and I hated it sitting unused in the gear closet.
This is when the idea hit me to use it in hope of bumping my IX UQ to a little lower temp. I knew I did not want to rip out seams or sew through the shell material, as it is Gore-Tex/water-resistant. I came up with attaching it using the drawstring closure and zipper pull at the head and shock cord wrapped around the heavily taped seams at the foot. Held up when I got into my hammock with it snug against the UQ.
It will have to wait till the weekend to get a test outside, but I wanted to see if anyone saw drawbacks with this system. (Other then the fact that it is 2.2lbs) I’ll post results after a night out.