No matter what I do my Shepherd will always choose my bag and pad as first preference. I've tried a few different things for him, last trip was a small fleece blanket. I'm thinking of an inflatable of some kind now after reading this thread, maybe take an older pad and cut it down and re-seal it. Hmm. The other thought I had was to find a cheap synthetic bag, cut it down and sew it up so it's just big enough for him, that too should fit in his REI dog pack.
This is a terrible pic, but you get the idea. Until I kick him off, he'll pick my side every time. When we're outside, any spot on the ground is fine, and at home, the hardwood floor is just fine half the time. But when he get's the chance he'll lay on my inflatable and down bag in a heartbeat, so he obviously has a preference.