Here is the challenge:
With a POD after the signing of the Treaty of Versailles, have Austria be as successful as it can be. It may not be a part of Germany at any time.
I think the most obvious would be having Italy oppose Anschluss, could be combined with some butterflies making the anti-German fraction(s) in Austria stronger.
Without Austria annexed into Germany, Czeckoslovakia is much more defendable, and Munich might easily end with a much different reslut. I also wonder if the socalled "Small Entente" of Czeckoslovakia, Romania and Yugoslavia will be more alive in a situation where the Germans meet more opposition.
Without Austria and Sudetenland Hitler's magic will be difficult to see and I think there is a serious chance of Germany going into chaos and perhaps civil war soon. That would make some kind of intervention from the neighbouring countries likely, but I guess the only foreign power that could expect some kind of popular acceptance in Germany would be Austria - so perhaps a foreign occupation force lead by Austria, and/or southern (catholic) Germany/Bavaria being annexed into Austria! If the chaos/civil war in Germany has any north/south (protestant/catholic) line of conflict I think the possibility of such an outcome is greatly increased. I'm in doubt however how much that meant in 20th century Germany. On one hand that line of conflict hasn't appeared overwhelming in Germany since the 30 years war, but OTOH it has been an obvious underlying fcator, and to some extent still is (very noisy if you ever have seen HSV play Bayern München).
German nationalism as born in early 19th century in OTL had no problems overiding the n-s or p-c line of conflict, but the question is what happens if the post WWI nationalistic "hope" expressed in Hitler appears to be a clear failure - will the Catholic Church step forward and will that have the protestants take a step in another direction? Perhaps our German posters have an idea? Personally I think communists will very fast be a main factor, especially in the north and in Berlin, and that this increase the likelihood of the south taking its own path, especially if Stalin utilise the opportunity to support his friends in Germany. So perhaps a "DDR" in eastern Germany, a "Federal Republic" in the the west (French vassal) and a Catholic state in the south, eventually in union with Austria, and with Italy as protector. This South German Union will still have issues with Czeckolovakia over the Germans in Sudetenland, and everybody probably will be anxiously (with good reason) watching if they find together with Hungary.
Regards
Steffen Redbeard