From my desk in a residential but dense area I can see 60-70 meters at any given time with a usb sdr.

Water meters in our area do the same, but since it is near the street and below-grade I can only see a few of those.

After having looked around for a while in disbelief, I now filter the capture from the SDR to just the ids of my meters. And I accept the fact that someone sufficiently-motivated could figure out when we're on vacation based on the broadcast consumption values...