Thanks Bosman. I brought almost all of my camping insulation with me, as well as my tent just in case I wasn't able to hack it. Turns out that I was able to survive ok in the hammock. The first night was uncomfortable, because I didn't have the foam pad set up correctly and it ended up shifting and exposing most of my back. I was setting up in the dark, and was in a hurry to go hang out with my buddies at the campfire so didn't pay much attention. That night it got down to 18F - I didn't sleep much at all, but survived.
The next night it only got down to 30F, but there was freezing rain and more wind. This time I wasn't taking any chances with staying warm, so I set my gear up during the day and did some overkill. First, I fixed the HHSS open cell foam pad, with the spaceblanket nice and neat. Then I put on my AHE jarbidge underneath the foam pad, but still inside the HHSS undercover. Here are a few pics I took just before I tore everything down to leave.