While working on a picoballoon and being curious about electronics at low temperatures I came over to information that the first thing to fail in an MCU would be flash and I could add robustness by executing the whole program from RAM.
So let's take an example where I have a battery (Li/FeS2) which is rated -40C but I can imagine that it can work for a while in -50C and more too. And then TPS61006 step-up, ARM and SX1276 LoRa module, everything else is expendable.
So what can be the main/most common failure mode at around -40/-50C?
From my uneducated guess, I'm worried mainly about radio module drifting too much, even sooner than -40C. But now I'm really curious about that flash thing and executing program from RAM; how beneficial it can be in this case.