I had that happen a couple of times last year. Fortunately, it wasn't a finished show. What I started doing was 1) save a copy to another folder, and 2)when I got to a happy place on a sequence, saved a new version. So I basically had Show_01, Show_02, Show_03 etc., just in case something went <md..
Then if something did blow up, I didn't lose everything at once. Saved my bacon a couple of times.