What about putting a quilt over/around a conventional bag to have a quilt for summer and add the quilt to bag for colder? If a good idea should I go with the same size as the sizing guides say or go a little wider? I have an old Big Agnes Lost Ranger 15 and looking at adding a Enlightened Equipment Revelation 10.
yup- I do that in the winter, have a 15-ish degree down bag and add a 50 degree Apex quilt, gets me down to 0 or a little lower pretty easily; on longer trips it helps keep the loft of the down by allowing moisture to migrate through the down bag and go into the synthetic quilt- which handles moisture better
if you plan on using a quilt in this way, you want it a little wider- and wider in a quilt is rarely a bad thing
EE has a good chart showing what temps you can realistically expect by layering what quilt of what bag/quilt
