In my current office I have 4 active machines which has the downside of producing lots of heat and noise. The iMac is the quietest, but the dual Xeon dual 1080GTX 256GB ram machine is the loudest.
In the new house, I want to have as many machines directly available, but without the noise and heat. To accomplish that I plan on having all of the machine hardware in the server room downstairs, and use HDMI+Displayport+USB over fiber connections to monitors in my office.
The technology for HDMI 2.0 over fiber is well developed and pretty cheap. You can get 4K 60Hz 4:4:4 extenders for a few hundred dollars. Displayport over fiber is bit more expensive primarily because the use case is more limited. There are some 4K 60Hz 4:4:4 extenders, but they are over $1k, and I have yet to find Displayport 1.4 over fiber adapters (but I can find some AOCs).
One interesting thing is that most of the available extenders use multi mode fiber instead of single mode. I am going to run 12 single mode fiber as well as a 24 multi mode fibers to the server room from the office to support monitor extension as well as some fast IP connectivity. That should allow me to have up to 12 extended displays, and lots of other bandwidth should the need arise.