Hi Ulana,
The D850 files are 8256 x 5504 pixels (2:3 aspect). I use the Epson 3880 printer which has a native resolution of 360 ppi. So before cropping you should be able to print as large as 22.9 x 15.3 inches. I don't think I've actually printed that large since with matting it implies a huge finished object. I have printed about 15 x 19 on several occasions. I know of several pros who make 24 x 30 inch prints routinely from 35 mm digital.
The digital files on our 35mm digital cameras have a greater resolution than medium format film, so it's no longer true that you need medium format to print large. Having said that, I do recall wall size prints at the Galen Rowell museum which were shot with slide film using a Nikon FE and cheap lenses. The other thing to remember is that the larger the print, the further back one stands for viewing. So it's not relevant to inspect a 36" print with a loupe. To print large, one needs to be careful with the processing, but that she be the norm anyway. Finally, there are programs which allow scaling up of prints (ON-1 Resize is the gold standard) should you want to go mega large.
JM
Thanks John. Most helpful.
The medium format prints that I am thinking of are taken with both medium format film and the Phase One camera. They are very large.