This would be my recommendation too.
75 denier interwoven with 170 denier.
Definitely not an ultralight, but feels bullet proof, warm as anything, still super comfortable when dialed in.
NOTE: if you have a sleeping bag with pad pocket or are using any sort of fitted cover, this pad is quite thick and large. Make sure your dimensions work.
The rule I've always heard is 1R for every 10 degrees below 70 as a \*minimum\* for survival, similar to how a sleeping bag rated at 0 means you'll be comfortable-ish around 10-20.
Following this you'd be looking at a R5-6 at 15-50 so you're right on the edge of that. Applying the same 'comfort' rule you'd want a 6-8 depending on if you like sleeping cooler (6-7) or warmer (7-8)
Exped Dura 8 (or DeepSleep \[R9\] if car camping) would be a strong contender for me in those temps. My philosophy is you can always vent heat if you're too hot in the cold, but if you're cold in the cold, you're cold.
The thing is built like a frikken tank, and I love it. Sure I could go lighter with the Ultra but I just love how strong the Dura line feels. I also have the DeepSleep for car camping and it's in the same vein. Very comfortable both, but I do love the added cushion in the foam mats.
I am the OPs size and the Expeds do very well. I have several, a shared Exped Megamat Duo, Solo Deep Sleep, and a Dura 8. All perform well and are very warm even in the cold. I've taken some down to 20°F (-6°C) and was fine.
R Value is cumulative so having 2 stacked pads will increase the total insulation. With that 2.2 + 4.x you'd be in the range you'd want to be for those temps. I use an Exped Dura 8 which is 3.5in thick (8.89cm) and works well for backpacking. When car camping I use a Deep Sleep (R9) that is 3in thick (7.62cm). Since both pads in question are about the same insulation value, I'd lean towards the thicker as long as it doesn't compromise your pack size or weight.
Exped Dura is solid as a rock and makes some very warm options at 5R and 8R.
It is a bit heavier but also a much thicker denier of fabric.
The Ultra series is a lighter version with thinner, more standard denier of material.
Exped is good, several models depending on what kind of camping. For reference I’m 6’ 330lbs.
MegaMat/DeepSleep used for car camping.
Dura used for backpacking.
You may also be able to use furniture foam which would be cheaper and can be cut to different sizes.
If you only camp in warm weather, opt for a 1r rated pad. I shelled out for the dura 8r because I winter camp. It is worth every single freaking cent. It’s more comfortable than my bed at home and it’s lasted for years.
Exped Dura 8 is going to be the more durable / warmest pad combination out there for an air pad.
If you want something cheaper that is warm you can look at the FlexTailGear pads. They have an ASTM pad over an R value of 6.
I’ve had an Exped DownMat for several years. It’s amazing. My last sleep setup was a Big Agnes bag with their Q-Core pad. Agree, too narrow and low R value.
Sold them both and got the Exped. I’ve slept in my truck bed, on a plywood deck, many times. The Exped is pretty damn nice, and I’m a 225 lb side sleeper.
Do it, OP, you’ll be glad!
Top Sleeping Pads on Reddit
1
Exped
MegaMat Series
92% positive of 462 users
Car camping comfort champ, but some side sleepers find it thin.
Agerak
