ESP32 has a variety of sleep modes down to around 12-20uA and up, depending what you want to leave awake.

With the 3rd CPU, the ULP, running continuously it is around 150uA and then you can be reading from i2c devices, or more. You can get that down to under 50uA with a periodic timed wake up, if you are keen.

Also it will appear as a USB device if needed when fully powered.