Thinking about making a top quilt for spring/fall temps, and to use over my 35* bag for winter. With the goal of using 2 bags to cover the 3 temp ranges. Is that way off base, or have people done this?
Is it fair to add the weight of fill and compare that to a known bag? Say: (1lb fill + 1.5lb fill bags) = a bag with 2.5lb of fill temp rating?
I will control the amount of fill pretty carefully to get to a rating that makes sense as a stand-alone fall/spring bag and to supplement my 35 for the colder months. How do you all determine fill weight to achieve a certain expected temp rating?
I'll be inside a bivy under a tarp, or more likely in my double-wall tent if I expect snow. On a therma-rest when the temps call for insulation. Would wear my 1lb down puffy too.
Second question, anyone made a quilt that you can fairly easily add/remove fill to save weight for a specific temp trip? Almost certainly going to work with synthetic fill. Down is great but I'm not confident in keeping dry yet. I could make horizontal tubes and just make one end have velcro, or even just overlapping flaps, so I can re-stuff it as needed. Will no vertical baffles be bad in keeping the fill even?

