I slept in my backyard again last night, with temps around 25. Instead of zipping my sleeping bag around the hammock all the way like usual, I left it unzipped about 1/4 of the length from the top, cut a old CCF pad to about 3 feet, and placed the pad lengthwise under my head and shoulders. The unzipped part of the sleeping bag gave it a sort of "top quilt" functionality and more wiggle room while staying warm underneath. Also bringing a small pad gives me something to sit on in camp
Now I'm off to try more systems to determine which I like best!