Usually, if you're whole Ironman run hinged on a cheek-clenching war, you'd feel like this if ironman randomized BS screwed you over.
And then you'd have to restart the whole run from the very beginning.
Well, you don't have to deal with that anymore.

First of of all, you'll need to make a desktop folder. Right click on the desktop, select "new folder" and title it something.

Next, you'll need to make a folder inside that new, empty folder to categorize your save files. You can't rename the files because the game recognizes them as corrupted once that happens. Instead, you'll need to make separate folders to distinguish between save games at certain points in time.
Next, you'll need to actually find your save files for CK2. The path directory is as follows:

You'll need to find your specific ironman save file within the paradox save folder and then copy/paste them into the categorized folders you have.

Be careful to keep one copied save file in one folder. Don't try to paste the copied file in the same folder as another because you might accidentally overwrite the other file if you're not paying attention and lose some important save.
Here is an example of how I have organized one ironman game's saves:

This is the pretty easy part. Now that you have a stockpile of old save files of your ironman saves, all you need to do is exit the game, open the paradox save file folder, find your current save file and delete it. Then you need to open your savescum folder and find the specific file save file for that run and copy/paste it back into the Paradox save file folder. When you reopen the game launcher, that save file will be recognized as the last save file played and you can click it to immediately continue your game. This also takes significantly less time to get back in game than just launching the game and then finding that save file. This way, you can save your progress and get back in game within 1 minute and a half once you get proficient at it. Enjoy your stress free achievement runs now kids!