Did two nights of car camping with friends in the woods of Milford, PA. First night started in the upper 20's then dipped to 19 with high winds. Did just fine in HH Explorer (inside a Guide Gear 12x12 hung as a doored tarp tent), JRB Winter Nest under quilt and Mountain Hardwear Lamina 20 mummy bag used as a top quilt. Being at the bag's limit I wore acrylic socks, fleece pants, Patagonia zip neck base layer and Northface fleece shirt.
The second night it dropped to 12 after sunset hitting a low of 7 overnight with relentless wind gusting 20-40mph. My setup was a KAQ between the Winter Nest and Hammock. A cheap Quest 0 deg mummy. I felt a cold spot under my butt right away but it took a while before I removed the KAQ. From that point on my underside was fine with just the Winter Nest. Big problem was the Quest mummy. It was too short and ultimately not warm enough. Eventually put my Mountain Hardwear bag over it as a top quilt. That fixed much of the cold problem but was extremely uncomfortable all night. Even in a properly fitted long mummy with the right temp rating I just don't think the mummy in a hammock is for me. It's far too difficult to reach out and check the UQ, roll over, etc. Time to start top quilt shopping.