Keep the pack. Go lighter if you want with a no-frills pack. I have a large volume frameless pack which is only 9 oz. Just a nylon bag with straps and a couple of mesh side pockets. A pad makes the "frame". I have thought about redesigning it to also be able to "unfold" into a full (or partial) bivy sack. Since I use a hammock year round I never got beyond the sketch-design stage.
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