Forgot to explain that if you use powerline adapters to resite the hub rather than using them as extenders with the hub remaining sited next to the ONT and connected by Ethernet lead, you won't be able to use them for wifi as well.
Surely there shouldn't be a problem as long as you only have one connected to the hub? The one connected to the ONT could be a hotspot
Personally I don't like powerline adapters, I think they're more trouble than they're worth especially if you want Multicast (BT TV) but I have used them and setup networks for others.
Because the pair connecting the ONT to the hub will be in the WAN not the LAN.
Thanks for these clarifications, very helpful again! Cheers.