I will echo Ilkka's comment. When thinking about moving up to a full-frame camera I borrowed a D800 for a couple of days to try it out. I was surprised by the proportion of motion-blurred photos at speed/aperture/ISO combinations that I would have expected to give good results on the D7000 I owned at the time. When I eventually bought a D810 I was pleased to discover that it was much more tolerant of low shutter speeds. At least for the way I support and fire the camera the D810 seems better behaved than my (admittedly brief) experience with the D800. The D850 shutter doesn't seem to be quite as well damped as the D810, but I've got used to it, and get by at slightly higher shutter speeds and ISO settings.
Cheers and good luck, John