I have a very specific question about NeoAir pads. I'm thinking of taking one (instead of a Prolite Plus) on a trip where the ground will definitely be cold, if not quite frozen yet, and the nighttime temps will fall into the mid or low 20s. My tent and sleeping bag are known quantities, and I have no concerns about them.

I'm wondering how cold you have used a NeoAir, without any additional pad (such as a CCF pad), and not gotten cold. For example, I know Oregon Mouse's answer: 40 degrees.

That simple, two-word answer is all I need from any of you. I have my own suspicions, but I've got no experience with mine below about 35 degrees, when it worked OK. (A BA IAC pad was cold at 25.) I'm not looking for hints on how to "improve" the range, just for anecdotal information on the coldest unassisted use you've had.