I can speak a bit to your sleep system. I used a Nunatak Arc Specialist (32 degree quilt) combined with a NeoAir short, the MB Down Inner Parka and Thermawrap vest down to the high teens last August. (18 was the predicted low and the ranger station when I left in the morning)I woke up a bit chilled once between 3am and 4am. It wasn't intolerable at all, and I don't know how much of it to attribute to the NeoAir(R-Value 2.5, vs your Ridgerest at 3.1, I think), but I would have been happier with my Alpine light down jacket on my torso. Of course, my base layer was also a Cap 2 zip top, vs the heavier Mondo 200.
But I would for a margin of error warmer torso insulation than the UL Down Parka might be advisable.
My legs were fine, surprising to me, in nylon North pants (fairly heaver at 17oz) with my legs on my GG Gorrilla pack and the thinlite sitpad, with Smartwool PhD mini crews on my feet.
Edit:Adding, I can't find the exact post at the moment, but it has been established that on frozen ground, your pad's need at R-Value of at least 5 to avoid losing body heat to the ground. If your Ridgerest is 3.1, you'll likely want to add something to that(R-Value are additive), like a Z-lite or similar at R-Value 2.2.
Edit again:The 1/8" torsolite has an R-Value .45 (Here's that thread about R-Values with data by the estimable Richard Nisley.