I can tell you from experience, a single PC is perfectly capable of running 10 man (at least in WOD).

I managed a similar team using a 6700k, 16gigs of ram and a single 980 TI. I ran my raid on a 40 inch 4k screen, and was running on stable 60 FPS at high settings. I'm going to be focusing on 5 myself for a while, I'd really rather do that and tag team with another boxer (or several) to do raid content in Legion.