I'm going to do a under quilt for worm weather. Question is this. When doing sew through costruction do you leave som slack on the under side? I was thinking 42 inches for the side that is agenst the hammock. 45 inches for the side that will hang. This will give me 1/2 inchof slack. I'm going to use 6 oz of down, the shell should be about 3 oz using Momentum 55. Hoping to use it to about 35* Any advice would be great.