Quote - "You could also try making extra save files, numbering each one as you go (or as I do, just have 2 and suffix them A and B)  then if one does get corrupted, you have a 2nd to go back to."

I do something similar as well and I thought everyone did it too. :-) In fact, I don't just keep two copies, I keep a lot of them. I number them and every second or third save, I do "save as" and create a new copy with a new number. When a project ends I may have 10, 20 or more copies. Then, to archive the project, I delete all copies except the last two.

I don't do this because of crashes (I have few), I do it because this way I can always go back to any past version, to get back this or that detail that I liked best. For example, I may end up preferring the atmosphere of the 7th version but the tree configuration of the 9th and so I can just go back, recover both and merge them in the 12th file version.

Although I have few crashes, I did already have several, of course. And it has happened to me that none of the saved copies would open again. Even copies that I hadn't touch since a crash. After doing the steps I described above (delete temp and/or env files), I was able to open the files again.