This is the reason why there are 3 quicksave slots of various age. Honestly - I play with a few mods that sometimes tend to break quicksaving (basically if the quicksave happens in map-editor mode with time paused after placing a specific building and rotating it a certain way it will corrupt the quicksave - this naturally happens often enough that I learned to place that specific building and then step forward one tick to prevent this...) and the 'thank god' moment when I realize that even though the quicksave slot is corrupted I still have one 5 min earlier that isnt is such a blessing.