Forester
Well just to give another path to follow...
I would "go to ground". Yeh I know the whole hammock camping cult will be waiting to jump me, but the extra stuff required for winter colder hammock camping could be more than just sleeping in a tent with an extra full length blue foam pad and an extra cheapo sleeping bag used as a quilt, or a light synthetic quilt from home just might be enough to keep you warm. I also wear only fleece in the winter as I shy away from compressible insulation layers, or wool because it does hold moisture that will end up in your sleeping bag. I want to be able to wear my day ski clothes inside my sleeping bag at night and I wear fleece to ski because it breathes, doesn't hold water, doesn't compress in a wind or under more fleece and my body heat moves through it so the inside of my sleeping bag is warmer and my hands don't freeze. I highly recommend a spare pair of light fleece sleeping glove that are NEVER ever used for anything else so they stay dry.
Jim