The German Army boots that usual soldiers can use for 2 years last only 6 month in my use. Before the Corona lockdown I really walked and travelled a lot, nearly all the year round.
This is my approach too. I use the Savotta under my bivvi and I have a Klimit Inertia Ozone mat for inside. The Klimit only adds 260g and offers much improved comfort and has a built in pillow plus increases the insulation too. Has worked well for me down to -14 which is the lowest I've managed to get out in.You might be better off using a combination of a closed-cell foam mat and then something like an Exped mattress on top. I've found the Savotta mat to be excellent in all seasons, as it protects the different 'comfy' mat on top of it, which I choose according to the prevailing temperature. It's probably a more flexible set-up than choosing a single mat for particular conditions.
Yeah, I've never been a fan of blowing into mats just for that reason. I use a roll top bag that fills the mat in a couple of squeezes: https://www.ultralightoutdoorgear.c.../klymit-rapid-air-pump-push-pull-valve-p12044@cmarkod
My Klymit Inertia O Zone RECON , sand, has not the holes cut out, the material is still there but flat, the rest is identic with the skeleton version.
Unfortunately I did leave it in Cologne one year ago with my other current equipment, because I brought old clothing in a large rucksack by train to Berlin where I got caught by the Covid lock downs and didn't yet go to Cologne to pick my stuff up, because I have enough of other equipment and clothing in Berlin.
That's why I did not yet try out how my Klymit mat works in cold conditions.
So, it very interesting to read your experiance here.
How do you pump your Klymit mat below the freezing point to avoid freezing breath moisture in it?
Did you get the Dutch mat? If yes what do you think of it?If one puts for example two British army closed cell foam roll mats over each other it becomes also warm, because the R- value is doubled.
It is less comfortable than an airmat of course but otherwise more durable.
My problem with the airmats is, that they aren't spark resistant. That's no problem if I can survive with just the closed cell foam mat underneath, but in really cold conditions it might become a bit dangerous.
Lower than -15 *C it's really a good idea to sleep by the fire.