Double vs 2 single sleeping pads in winter – how much warmth difference?

The type of pads and the type of ground you sleep on are important considerations. The classic winter setup for snow camping is a CCF pad under an insulated inflatable. The CCF will not compress and let your body “touch” the ground. The inflatable pad will compress and can easily let your body “touch” the ground in the hip and shoulder areas, unless you have a CCF pad underneath to shield against that.

Sorry to clarify, I mean warmth of a double wide vs two single, side by side pads for use with a double quilt or double bag. I’m familiar with the insulation loss with compressing inflatables, but I imagine this doesn’t differ much with a single wide vs a double wide set-up (?), though perhaps any compression could make for a draftier seam down the middle with two singles?

I’m not quite set on the pad setup yet. I have xtherms, which have worked fine with pad straps and no ccf underneath to around 15F, but I’m wondering about either switching to the thicker exped down single pads for colder temps, adding ccf to the xtherms, going to the exped synth duo pad, or doing a pulk and a base camp with two single Megamat 10s, which are nice because you can also convert them to a comfy sofa, vs a Megamat Duo, which is less versatile, but maybe the ultimate in warmth/comfort for a winter base camp.

To OP,  your reference to the spoonbill and straps, leads me to believe you are asking about a set up for two people right?.  Not just how to deal with colder environments (like snow camping) where you can stack two sleeping pads to increase their R-Value.

I don’t have experience with a double wide – single sleeping pad, but I would imagine that they would be warmer (given the same specs) than two regular pads side by side joined by strap where you have a gap in the middle where cold air get thru.

In winter / snow backpacking, when I hike with my girlfriend, each of us carry two sleeping pads. One is CCF and one is Inflatable and set them up as Lester suggested.  I like to have two pads as the ccf pad also works great to seat on the snow when you are taking breaks or doing chores at camp, etc.  Also if there is a fail on the inflatable one, you still have something to get you thru the night.

That being said, and back to your original question, I have the pads staggered so there is no straight vertical gap between the pad layers set side to side.  This works well as we have one pad that is normal width and one is a bit wider on the CCF pads. I hope this makes sense.

Nice idea for staggering the pads, I bet that would mitigate any warmth difference between 2 singles vs a double wide (and yes, for a couple). The megamat has an internal mix of air and foam and a very high R, so I think it wouldn’t need any added ccf beneath it as a double, unless maybe using two singles to deal with the air gap. They are already so bulky, I would hesitate to try to get yet more foam on a pulk…

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