Ask HN: Advice for deploying Arduino hardware into remote environments?

I've been building out My First™ Arduino project recently. The prototype has a few pre-sales already. Much excite.

The gist is that I'm providing hardware to control a 6V motor and a web app that allows users to configure the motor's schedule remotely. The motor is going to be out in the wild where game hunters hang out and it's going to dial home over a cell network once per day to log stats about itself and learn any changes made through the web app. It all runs off of a 6V lead acid battery.

I've never done anything like this before. I've been a strict full stack dev my whole career, no hardware. I was using GPT to figure out how to wire everything together and how to write the C++ to run the device. I'm going to ship with off-the-shelf boards connected together via screw terminals for the first few devices and then look into getting custom boards made later. This means I've got a voltage sensor, buck regulator, relay, motor, MCU, etc. all on separate boards for the time being and a bunch of wires running every which way to make all the power needs work.

I know this is a little vague, but I was wondering if anyone had any hard-earned lessons they wanted to share about similar projects? Data you realized was important to log that you weren't logging until after disaster struck? Unexpected issues with power management or connectivity? Things that go crazy in Arduino/low power environments?

I guess I'm just looking to bolster my confidence beyond writing a bunch of tests for my code. It's a little scary knowing my code is going to be running on hardware where if things go wrong I can't just push a new version.

Thanks!