If the Virgin Help page is correct you should be able to do the latter as long as you:

1. Remove the VMHub's modem-mode IP (192.168.1.100) from the DHCP pool of your router. If you can't remove it, reserve it to the VMHub's MAC address.
    
2. Change the gateway address in the Router's DHCP settings to 192.168.1.100.

First one will be required to stop the VMHub's IP address being allocated to the DHCP client and the second will inform the DHCP clients to use 192.168.1.100 as their Internet gateway.

Of course, this is all dependent on whether your new router allows you to specify the gateway for DHCP. Quite a few don't, instead assuming that it should be the router's IP address.

Thanks Matt.

Well Yodel didn't leave the router at a neighbour so I won't be doing that tonight.