A few days ago I got to thinking on ways to compact my bag, the proposed solution I had was to instead of using a intermediate sleeping bag and bivy. I would use two patrol bags and a bivy. Hoping to cut weight but at the least down size the kit to a more compressible set up and still maintain similar cold temperature rating. They seemed to weigh the same and take up the same mass. The upside to this is to be able to use the kit in drastic temperature shifts, (Hopping freight from north to south in winter) and to be able to give away or trade an extra bag when not needed anymore. It also solves the problem if one sleeping bag zipper breaks I have a back up, and if one or both bags get wet, theyll dry faster then the thicker intermediate sleeping bag in the mss. Im not sure if it'll be as warm though. Its what ill be using on the train to nola this winter. Anyone else do this before or have any opinions?