We've had a Hub 3 for some time, set to Modem mode and use a TP_Link router to manage wi-fi and direct ethernet cable connections.
I assume that i need to install the new Hub 5 in 'normal' wi-fi mode first, make sure that is all working and then turn it off, plug in the cable from my router and then switch to 'Modem Only' mode.
To do this i further assume that i will need a device (laptop) connected to the Hub 5 (either wirelessly or via ethernet cable) when it is in 'Normal' mode so i can get into the Hub and switch it to 'Modem Only'.
NB I wouldn't bother, but i got an email from Virgin saying my copper-wire landline is going to be pretty useless in a few months so i needed to upgrade.
Hope that makes sense
Ok to do a stated, but make sure, once in modem mode, that the VM hub is powered on last. As for the landline it would work ok with a Hub3.