What Jack said... and probably what Steen said as well. If price, size or weight isn't a problem, the D810 is the camera to have. It's nearly faultless, and the 24-120mm is more or less tailor-made for it. It's a surprising lens, for it isn't all that expensive, and despite its 5x zoom range, it's a very solid performer, sharp, good contrast and colour and easy to work with. There is some CA, and I struggled with that on occasions, but again: it's a 5x zoom.
Although I haven't tried it, the D7200/16-80 combo that Steen suggests will probably produce images that are indistinguishable from the above combo on most occasions. It's a bit handicapped at the long end, since he relative aperture is smaller there, and the ergonomics aren't as fluent. It's smaller, lighter and cheaper though, and those are deciding factors for many. When I sold my D810/24-120, the reason was not the size and weight of that combo. It was when I started adding stuff that it got out of hand.
That is the danger of any one body/one lens combination; when you stand on he deck of a river boat five hours from the coast of some obscure country near the end of the world and you see this farmer with his buffaloes and they are just tiny dots in the viewfinder... that's when when you wish you had taken that extra kilogram of glass. Or when 24mm just isn't wide enough for the group photo that you need and want and there's not enough light and the edges aren't sharp enough for a problem-free stitching. And so on...
So I made a habit of carrying a 21mm (Zeiss) and a 180mm (Nikkor) in addition to the 24-120, making the kit twice as heavy while still not having a backup body other than my Nokia. That also made me realise that, although the zoom is very good, there are occasions when a quality prime really, really outshines it, and I'm not talking about pixel peeping here.
If I'm going to carry the weight of a Nikon DSLR body, I might as well carry the best lenses I can afford as well. If I don't, I might as well "downgrade" to a smaller format. Which I eventually did, but there were many reasons for that that are not relevant to discussion.