Here's the Hitler escapes scenario. It mixes history with a little bit of fiction.
On May first 1945 (days before the war ends), Oberleutnant Wolfgang Klemusch of 3(F)SAGr 130 at Copenhagen Denmark is ordered to fly his BV 138 to Berlin.
He takes off at dusk arriving over Berlin about midnight where he lands on a lake. There, a party is waiting for him. They come aboard, along with some wounded soldiers. Among the passengers, and unknown to Klemusch, is Hitler. Klemusch takes off and arrives safely back in Copenhagen. Hitler and his escort go aboard a KM Vorpostenboote
And head out into the Baltic Sea where they meet a U-boat on the surface and transfer to it. This is a smaller Type VII, so it can only make a one-way trip to Argentina / S. America. The 46 man crew along with Hitler and several bodyguards heads to sea. Upon reaching their destination, everyone is put ashore and the boat is scuttled.
Klemsch's flight is an actual historical one. The rest is fictional, but at least somewhat plausible. If the aircrew and vorpostenboote crew didn't know Hitler was among those taken aboard it is possible that only the U-boat crew knew and since they were with him in S. America, the secret is kept that Hitler escaped.
In S. America, Hitler's health continues to deteriorate and he dies in obscurity.