You can put the ESP32 into deep sleep, and it can wake based on a timer, or it can run the ultra-low-power core which is a very slow, very low memory, very low power core. It's good enough to look at ADC or I2C devices and do a little math. This can be woken up fairly frequently to check a sensor, and say, compare against a previous measurement, and then wake up the main core if you need to process the measurement or do WiFi.

I think you're right that this won't work well with a CR2032, but if you're careful about using good voltage regulators it can last a long time on 4 AAs.