If you haven't tried loading the save, or the earlier version of it since they rolled back, then you can opt into the 1.30.5 beta in Steam. Open the client, go to the EU4 page in your library and click on the 'Manage' icon (the little cogwheel icon), and under Properties -> Betas you can select the 1.30.5 version. Let the game update then launch it and on the loading menu hover over your saves to see if they still say 'Ironman: YES'. If they do, load them up, and you still can continue, at least my own Ardabil game is fine and still eligible for achievements.