Didn't make it to Virginia - too much snow, too cold to be experimenting (my buddy went, and bailed after a day and a half due to the snow.)

However, I did go out yesterday with a small group to a local park that allows backpack camping. It was 23 degrees, with about 4 inches of snow on the ground, when we left the trailhead. It was a 3-mile hike, so a perfect chance to test the NeoAir (and some other new gear.)

I stamped down a tent site (snow was powdery, so it didn't turn to ice when stamped; it also didn't melt and soak things - just brushed off.) It's been cold here; only above freezing about 1 or 2 days since New Year's. The ground was hard, but not completely frozen; I could push a needle stake in with my boot. I didn't use a footprint. I inflated the NeoAir pretty full, put it in the tent, and never messed with adding or letting out air. (Didn't want to add any more variables than I had to - gee, that makes this almost sound quasi-scientific!) I was using an MSR Carbon Reflex 1 tent, with the vestibule zipped shut; a non-mesh tent might have affected the results a bit. It was also dead calm, with no breeze whatsoever.

I was using a 20 degree WM Alpinlite sleeping bag, and started out wearing midweight long underwear and socks with just the 48 inch NeoAir (my empty pack was under my feet.) When I went to bed, it was right at 20. As it dipped below 15, I added a wool balaclava and some down booties. I could feel the pad getting cool, but not uncomfortably so, so I didn't do anything about it.

At 10 degrees, I finally put the Z-Lite pad underneath the NeoAir and put on my WM Flash jacket (hooded) and Flash pants. Slept plenty warm at that point until it hit zero around 5am, when I woke up from being a bit cold in the small of my back. (You know, that little spot of cold that's just enough to keep you from getting back to sleep.) At that point, I put on a WM Flash vest under the jacket, and conked out until about 7:30, when everyone started rousing.

So, I'd probably trust the NeoAir to about 20 degrees, and carry a Z-Lite backup pad below that. I do want to stress that this is specific to my own use, in Ohio, Kentucky, and Indiana, when it's cold but the ground isn't completely frozen. With a different sleeping bag, different body size or metabolism (i.e., being a "hot" or "cold" sleeper), and different conditions, this range may not be accurate for you. About the only thing this thread really does is collect a lot of anecdotal evidence about the NeoAir in one place - and that might help someone else.