Smart meters to cost the UK billions: 2G switch-off means replacing 12-13 million
(www.theregister.com)
Wait, why are the individual meters wireless at all?
It seems like if you're running a power cable for ~200 A service (Idk what UK standard is, but that's what I used to in US), running a small fiber cable in parallel would be trivial - and I expect the data rates coming from these would make a fiber connection "future proof" in the most literal sense of the word.