No, I haven't. I'm a bit of an EFM32 fanboy. I like the low power features, development tools, Linux support, and open source hardware/software. I have the comma.ai panda for reading data off the CAN bus through the ODB-II port on the van. That has the ESP8266 in it which is the predecessor to the ESP32. Sounds like a fun project. My victron charge controller has a built in load disconnect when the battery voltage drops too low so I don't need to build that. I'd like to add a CO and maybe gas sensor to the board if I ever get around to it. I hear ya on the money.
RE: Cold Nights