When I'm hiking with a camera, it lives around my neck on a BlackRapid strap positioned over my backpack straps. If I have to get the camera out of my backpack, far too often I don't bother with the shot. The exception is in really active rain conditions, where I will try to get it some extra protection. On shorter (day or single overnight) hikes, I will carry a Gitzo Series 1 tripod in my backpack or in the outside compartment, but the tripod isn't really compatible with my longer hikes, although I've considered one of the new Gorillapod models to have something, and I certainly improvise quite a bit from the Rock E. Stone school of camera support. This type of photography puts a huge premium on toughness and sealing - not everybody needs it, but I really do. IBIS or a well-stabilized lens are also essential to me, since there are so many times when a tripod is too heavy or not to hand.
So far, the best option for this combination has been Fuji (assuming the weight of a D850 and a pro zoom or two is too much, and it is). Nikon has offered me an option with double the pixels and improved DR in the Z7. I'd rather have dual card slots, but I see Thom Hogan's point that a single XQD is probably not the most likely point of failure in the camera... I can't afford the weight to carry an extra body, but I will have one ready to be mailed out if needed (if I carry a Z7 on my next long hike, my backup will be Fuji, rather than a second Z7, because I can't afford two of them...).