My phone service has recently switched over to the Virgin Fibre Network. Unfortunately, with my current setup of where the Hub is (attic) in relation to where the phone needs to be (4 floors below), a connection is not feasible. So I have opted for a broadband only deal.
However, is it possible to keep my Virgin Media Fibre Optic BroadBand, and have a different provider for the traditional landline service?
Nothing to stop you doing that but any new provider is likely to offer a phone-via-router connection too as all providers are going this way.
Might be easier to get some cordless phones to use with your setup (base station in the loft and cordless handsets around the home as required).
If you have ethernet network cables coming down from the loft you could repurpose one of those to take the phone connection from the loft and carry it downstairs.
VM should offer to modify your home phone wiring free of charge so that your existing extension sockets are linked into the phone socket on the hub but VM may struggle to do that over 4 floors though due to VM's working at height limitations meaning an internal cable route would probably be required.
Alternatively, find a local telecoms tech to fit such cabling.