An unanswerable question I know...
I've been looking at various gear lists people have for the CT and bag temps seem to be all over the map. I sleep warm and am leaning towards my 35* WM bag for a CT thru beginning July 22 and ending around August 13th-ish)
A lightweight silk base layer and 35* bag weighs less than my 20* bag so I'm leaning in that direction.
Sound good? If temps were going to go into the mid-20s I'd probably suck it up and carry the 20*.