For what you describe, I'd use SDI. The blackmagic micro converters are good enough, and cheap enough that carrying a couple of spares isn't arduous. The SDI input to HDMI output have an SDI loop out, so you can link on a bunch of Screens if needed. They are USB powered, and typically are quite happy powered off the USB port on the back of the TV that they're feeding. HDMI fibre is another way of doing it, but they can also be quite finicky and are really quite expensive! If going down the SDI route, It's worth looking into the cost of pre made cables vs buying bulk reels and the right tools. We make all of our SDI now as it's a surprisingly quick job and a lot of the stuff we want is custom lengths. It's also very convenient just having a drum on the shelf and being able to turn it into a couple of 1m, 5m or just a 30m!