You should be able to do that - via a splitter adapter and extension lead(s). Your only working telephone socket on the hub for one line will be TEL1. For further information on the switchover and issues to do with telephone extension sockets have a read through this page
https://www.virginmedia.com/help/home-phone/virginphone/switchover
if you have not done so already. Read the bit about 'You’ll need to book a free technician visit if:' near the bottom of the page to see if that helps you any.
Alternatively, consider using some cordless phones. Plug the base station into the VM hub and use satellite cordless phones around the home as required.
