I have a greater swiss mountain dog. I started by getting him used to camping with tarp in the backyard and sleeping in the van, we've also been doing a bit of winter camping in a friend's garden.
He doesn't like sleeping away from home, but then he also doesn't likes being away from me. He anyways spends his nights outdoors, so temperature/fur is no problem. (His breed is typically farmyard guard dog or livestock guard dog, so he's a barker. So rather no stealth camping. He'll growl or bark when animals move around closely - which is fine if it tells the wild boars to make a detour, but rather annoying when I wake up because some racoons came along in the tree)
Tarp + tethering from a tree works well. I haven't tried a tent. Put some thought in where to tie him to minimize the chances of getting entangled with the lines of tarp or tent.
Pad: a dog quickly recognizes that a pad is softer and warmer than the soil. If they need that, they'll use it (unless they decide it's in the category of things they're not supposed to be on). I'd put it to their use at home for a while.
My dog will scratch a pad like he does when making a cozy sleeping place with his mat or some leaves and soil outdoors. Foam pads will quickly be in shreds, I'm thinking to experiment with the cloth of an old dog mat as hull. At around 0°C, he uses a pad if available. If they don't use it, they don't need it (they may prefer to make their own camp from leaves)
Feeding: my dog needs substantially more feed when hiking the whole day, and also in cold weather (probably also because he's able to run more in cold/cool weather). I observe roughly a factor 2 between full hiking day in winter compared to hot weather in summer. (But then the mountain dogs really don't much when lazy.)
I'd do a bunch of single-night out test hikes before starting on a whole week.