Ran out of storage space, freed up space, `_temp` dirs remain

[HammyHavoc]

I ran out of storage on a disk during a run of the script, freed up space, re-ran the script, but _temp dirs remain, and I can't seem to get the script to continue where it left off.

Uh oh.

[HammyHavoc]

The above PR closes this issue once merged (and a lot more).