Likewise, see my edited post regarding Digital Voice.
Since you mentioned that wifi coverage was an issue, perhaps invest in a wifi mesh system.
I use Netgear Orbi RBK50, which is a two box system.A router that lives quite happily with BT FTTP and one satellite. You can add extra satellites if needed.
Works a treat.
Thanks for the pointer and all the help from you both, hugely appreciated.
Sorry guys, seems I've hugely misunderstood what Digital Voice is and I thought it was just an optional perk. BT have just told me our copper wire landline is obsolete, and we have to connect to the Smart Hub 2 to be able to get the landline working, which is a necessity for this household.
I've just ordered a very good new router so I am still keen to use it, though BT are kindly providing us a free extension disc, however I have no clue how good they are.
In this case, will it be connecting the router to the Ethernet port, changing its IP address and such, and turning it into the access point? Will this preserve the landline?
Yes.
See how you get on with the disc before jumping in with a new router.
Now I have actually noticed that on the Netgear configuration page, I can change the router to AP (Access Point) mode. Should I still manually set the IP information as you said or use their dynamic option from existing router?
It will probably obtain the necessary addresses if you set it to get them dynamically. It will just act as any other device issuing a DHCP request to the hub.