But is this system still in active use and planned to remain so? Over here, meter switching traditionally was done using audo frequency switching (superimposed on the mains itself), but this is being phased out and replaced by systems for remote meter readout over GPRS. The support for day/night switching on traditional meters will end in about a year, from then on passive meters will only offer single-tariff.
It is not so bad as it used to be. GPS receivers can operate in a building, certainly when only used for network-grade time referencing.
VLF in concrete buildings never worked great, it sort of worked but with limitations. And interference from SMPS is not the first problem, in the past interference from CRT monitors was also a big problem.
With a suitably placed outdoor antenna it will likely still work fine. (stronger signal and weaker interference)