Good morning Andy,
I use two x 5m active repeater USB cables, that go from my control room, via a mains powered USB hub. At the pier end. I use another 4 port hub, this is powered via a 12 volt portable supply, made for a sony play station.
I plug all my imaging gear and other equipment into this hub, and then control all, from the “Whirlpool Observatory”
The secret is. “HOT” glue the extension cales, to prevent moisture from causing drop outs. I also have all my USB cables Hot glued into position on my pier.
I and another imager from my society. Have never had any problems with loss of single.