You had me until WiFi ping. One thing you learn doing electronics with batteries pretty quickly is that WiFi just destroys battery. Even just turning the radio

You had me until WiFi ping. One thing you learn doing electronics with batteries pretty quickly is that WiFi just destroys battery. Even just turning the radio on (which you must do for any low power device, they are idling in deep sleep otherwise) is going to cost you orders of magnitude more power than anything non radio related. The most efficient devices that ping something on battery use some alternative low power protocol that isn’t full WiFi. The story around BLE is significantly better but also the rise of thread and Matter makes these alternative ways of communication more viable these days.