Gaming PC in one room but play it in another
 

Quick question, I want to have room scale VR, the only room big enough would be the living room. I would expect the PC would need to be in there for length of cables etc.
That's ok, but when I'm not VR'ing I would be upstairs in the box room where I am at the moment using a PC.
Is there anything on the market that would allow me to have the PC downstairs yet effectively control it and use it as if it were still in my little cave without inducing a load of lag?

Steam Link may do most of what you need without costing a lot of money or being technically challenging.

I've got a steam link at the moment but it goes the other way (PC in the box room/gaming in the living room). I did ask at the time on Steam whether you could drive the Vive with it but got no response, if that were possible I'd be sorted.
My pickle is that I have triple screens upstairs which I'd like to retain so the single HDMI connection that the Steam Link provides wouldn't do this.

Why not consider an amp that does two rooms or a longer monitor cable as descent GPU's do two monitors and get a good wireless keyboard mouse setup that can be used over say a 10m range even though you don't need that distance.

It'd have to be a bloody long monitor cable, can you get them that long?

Just buy another PC for the mancave, good excuse to get something up to date then ;)