LPL's new TPL5110 Breakout board (
https://lowpowerlab.com/shop/TPL5110) offers precision timing, high current switching, with nanoAmp quiescent current.
So, if you just happen to have an application where you want the convenience of a powerful, but power hungry device like the ESP8266 to take a random example AND you want it to run for years, not minutes, on a battery, this is just the baby to do it!
The TPL5110 breakout combines the very precise and extremely low power TPL5110 timer with a high current load switch. This device will consume 35 nano amps when timing and will switch multiAmps when it times out and turns on the load. In this application an ESP8266 WiFi load, which draws up to 225mA when connecting and can only dial down to a few milliAmps when sleeping, starts up, reads a moisture probe, connects to WiFi network, reports the result, and then tells the TPL5110 that it's done. The TPL5110 then shuts off the load and goes back to timing - at virtually no current.
One CR123A will drive this circuit for a year.
Enjoy...
UPDATE: added photo from PDF: