Throw down an emergency space blanket underneath your pad? Wonder how much that would help. Some of these pads sound like that's what's inside as loud as they are.
I carry a longer section of a thermarest z-lite as a glassing pad primarily. I think it's 6 sections, but it makes for a torso length sleeping pad, covering from my shoulders to my knees. It's nice to double over for some extra cushion for sitting, or laying out for a mid day nap or shooting prone, or if you got stuck out for a night.
But I'll also put it under my sleeping pad at night, mostly for a little extra protection underneath, but adds the R value. It also saved me one night this September when my pad went flat early in the night, I was able to make it through the night and fix it in the morning. It's starting to get pretty beat up, but I'll replace it and do the exact same thing when it's time.
The extra 2 R value of a z-lite would put you over 5 under the important parts, and it's a multi purpose piece of kit. I was using a nemo tensor extreme last year, which is an 8.5 R value, so I didnt need the warmth, but i might try saving some weight with an Xlite or something paired with the foamie.