Yep, if this is going to be used primarily for hanging I would be looking at a quilt and not a bag. Also IMO a quilt is more versatile if you decide to go to the ground. I have two Jacks R Better quilts and I'm very happy with them. Well constructed, light for the amount of loft, versatile and reasonably priced. They even ship fast.
If you only travel on sunny days you will never reach your destination.*

* May not apply at certain latitudes in Canada and elsewhere.