In my engineering 9-5 I’ve done a number of FMECAs and if the product uses new technology or processes I’ll get my vendors to contractually sign up to doing one as well. They’re great if you have solid data to feed into it. One of the oft used mitigations is having redundant systems (dual boot ROM etc), which is literally as Bill said “packing your fears”. The whole UL ethos pushes back against this but other methods can be considered and are available.
When I used to run programs, I would apply project management risk mitigation practices. Similar to FMECA it attempts to quantify probability and severity but would also add expected monetary impact which is a way of quantifying severity with its actual effect. For backpacking we could do this by assessing severity against injury, hunger, hypothermia etc
What I do when venturing somewhere new in shoulder season is pull as many years of weather data off the gov’t data bases. Ideally day by day granularity. In Canada I can pull this down as a .csv.
I then run some stats against it to determine the average and sigma of the temp swings, plus the records.  Once you have the sigma, you can decide how much risk you want to take by following the 68–95–99.7 rule and assessing the severity of getting it wrong. Will I get hypothermia? A bad night’s sleep?
A few years ago I awoke to a record low and just barely had enough insulation to get some sleep but I was being extra cautious, not having been to that area before.
Last 4 days I did some long miles so needed good rest and recovery. The first night was close to freezing and yesterday was quite hot.  I had just enough cold weather gear to get decent sleep the first night and my planned water stops let me pull in on my last quarter liter in the heat.
This takes a lot of planning and I think 99% thinks its overkill and won’t bother. The benefits extend well beyond safety though, as it makes for a more enjoyable trip by opening up new possibilities for example by not overpacking or over-stopping.
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