I would like to try some strategy variants off of particular point in time snapshots and then reload back to the same situation in order to explore how each approach would work.
The save game system however seems geared to just update the same file and overwrite.
From your experience is there any immediate or "down the road" stability or functionality issues with backing up the file that is specified in an in-game save and then restoring it to go back the original "snap-shot" ?
Sometimes there are caches or other files that come into play aside from the main save file in situations like this.
Just make a folder outside the game, like on the desktop, copy and paste all files in the current game folder into the one on the desktop. Do your worse, as they say, then clean out the game folder and replace with all files on the desktop.