I have two SIM Comfort 5 LW mats that I use for similar occasions, which I have found to be really comfortable. They're great for me, and I can only imagine how good the 10cm mats would be to sleep on. Probably amazing.
I reckon you might be better off with two singles, and these are some things to consider on the single vs double question:
- If you have a puncture in a double, then both of you will be affected by that horrible occurrence.
- As you probably know the singles have velcro to join the two mats so they don't both creep to different sides of the tent. I've never been bothered by the tiny gap in the middle where they join, but it might be worth seeing if you can try out both in a store, as it might be annoying to others.
- If it is just yourself one night, then the added flexibility of being able to take a mat just for one, instead of something huge for two, also seems like something in favour of two singles.
Just my opinion based on what I know of the mats I have. If I had the Megamat or the Comfort Duo then I probably would have written something entirely different
