A VBL bag will definitely work. I do have a couple of problems with it. First, it's a bag. I dislike VBL bags for the same reason I choose a TQ over a sleeping bag.
second, I HATE getting out of those things in the morning (or middle of the night) in the cold while I'm wet. VB clothing at least lets me move around under my TQ, and I can swap for dry clothing "one section" at a time come morning.
It is a real kick in the butt, coming out out a VB on a cold morning. That hits a lot harder than coming out of a warm jacket. All of which just demos how well it is working.
Apparently, signature that I used from 2006 no longer tolerated so now deleted.