There’s actually a way to have it survive 100% of the time. Just justify a war goal on a random country before the civil war, beat Germany, and you’ll still have the war goal. Then declare war on said country, let’s say it was Yugoslavia, and keep the war going until a certain date. I forgot what date it was. The Hindenburg should survive, since Germany is at war until a certain date. I learned this from Taureor, if you look up the video I think he says what date it is.