what I finally did on my winter under quilt.... First, I cut the bottom (the side you see hanging) material wider and longer than the top (the inside material that's up against the bottom of the hammock). The other thing I did... my baffles are 4" tall and they all run from foot to head. As they run to the middle of my quilt the chambers get wider but on the ends they are a bit more narrow. The baffle height of 4" is also reduced at the foot and head end. That way I didn't have to have as much extra bottom material to wrap over to reach the top material. I've been testing this quilt lately during this cold snap, we don't usually get temps that stay around 19ish like this very often. One thing I would have done differently would be to have added a bit more down into the chambers that are on the outside edges. I've been warm and toasty but have noticed that as the quilt comes up the sides of my hammock, that the down wants to settle lower.
This is probably starting to sound like I've got my head stuck in mud too...
TinaLouise