I've aquired two down pillows with 39 oz. of 600+ fill down each (78 oz total) and am starting on design of an ultra heavyweight winter top and bottom quilt set for my hammock. Because this will be used only for winter camping only the overall weight of the final product is not as much of a concern, but I am wondering just how much of the down I should use. Thanks to the great calculators developed by forum members (Meteor and gt7599a quilt spreadsheets) I am able to calculate just about any weight quilts, but I don't really know how that will translate to warmth.
Has anyone had experience with either DIY or custom made down quilts targeting sub-zero temperatures? And how much down and and at what fill power have you used?