An intriguing possibility is that the execution backfires because the Nazi leadership had a war to inspire the public so they didn't really need Hitler, and could make much smarter decisions in his absence, and so the Nazis actually win the war (or at least achieve a settlement in a much smaller war which leaves them still in power). But I guess it's also possible the leading Nazis fight each other like rats in a sack over who takes over, who was to blame for the assassination, what military action to pursue next and why were they going to war alongside the hated communists against everyone else in Europe in the first place, and the whole thing falls apart very quickly.