I've always thought about moving to naked DSL and a VoIP service but I always then stop and think about how I could manage multiple extensions in the house.
Assuming you connect your model and VoIP phone to one jack so there's one phone there, even if that phone has an extension socket to plug in another phone, it becomes problemmatic when you have phones in several rooms across two stories.
I don't think it's feasible to use cordless phones throughout the house so I thought of another solution.
There are two lines into the house, with one line terminating at all extension jack points (5). The second line terminates at only two jack points.
I could put the naked DSL on the second line and then run a cable from the modem/phone to outside the house and connect it to the second pair in the junction box. That would mean all extensions in the house would have connectivity to the modem/VoIP phone.
Does that sound reasonable?