Ditto. I did get a touch cold but that was because I had mine adjusted incorrectly. I luckily was car camping and had brought an extra fleece blanket. I put it on top of the PLUQ and re-adjusted the shock chord. It worked well until the coyotes woke me up.
I'd say that the low for this UQ is high 40's, low 50's. That's just for me personally as everyone is different. I'd love to try some IX or even PE inside of it for more warmth and see how that does.