Humidity is unlikely to help: I have temperature/humidify BLE sensors all through my house and humidity varies wildly. You'd have to do some sort of calibrated

Humidity is unlikely to help: I have temperature/humidify BLE sensors all through my house and humidity varies wildly. You'd have to do some sort of calibrated long-term machine learning thing to maybe pull out the data. Much better would simply be digital water meter tracking (which is still amazingly hard to actually do) since when all the taps are off, if you still have substantial water use then you probably have a leak (I would really love a decently accurate ESP-based water meter with like, Sharkbite fittings on it so I could check the water flow out of all my taps or something).