Best ESP chip for low power?

1

I am running ESPHome, and have a couple battery based temp/humidity sensors. No power available in those areas. I am trying to find the best board for this use? I am going to build a step down to 3.3V from 3.7V, based on this info: https://randomnerdtutorials.com/esp8266-voltage-regulator-lipo-and-li-ion-batteries/

However I am looking for the best board to do this with? I will be Wifi and MQTT for coms. Wake every 15 minutes and deep sleep. From battery powering the Wemos D1 Mini I run at 75mA and deep sleep is at 6mA. This testing is currently running off off a 18650 battery with a LD1117V33 to step down.

So what board gets me down to a true deep sleep?

2

I would go for one of the most basic ones, like ESP12 or maybe even ESP1 and connect an external USB-to-serial adapter to the RX/TX pins for uploading the firmware for the first time.

6 mA is quite high for deep sleep and battery powered applications. You would want a ESP board with as few extra peripherals as possible. No USB-to-serial IC, no leds and such “unnecessary” features. Also, does the Wemos have an integrated voltage regulator but you are using an external LD1117 regulator? If so this not used regulator might draw some small current depending on the model.