I made this top quilt to mimic an Apex EE quilt. They don't run lower than 20 degrees so I made my own. It's incredibly quick and easy. And it's very forgiving! It came in at 2 lbs for a quilt that should be great below 10 degrees!
The dimensions drawing I have is for a person of smaller height and width. I am 5'6" and I sleep on my back with a width of 56". Please adjust if you are larger or sleep on your side/stomach. You may have to get another yard of fabrics to do this bigger. The dimensions drawing I have is in inches*10. So 5.6 is 56 inches. (I didn't feel like adjusting the units in AutoCAD).
You can add push buckles to this if you want a looser fit. Just sew them in with elastic during step 3 in between the two fabrics.