I subscribe this solution if we are to keep the OTL end of the war in place. IMO the best PoD to realize this is Stalin losing confidence in the perspective of neutral united Austria as a lure for West Germany, and hence supporting a Communist takeover of East Austria/Vienna in 1949-50. IIRC there was a Communist strike in 1950 that could easily blossom into a coup in the Soviet zone. The democratic Austrian government and poltical parties would flee to the Western-occupied zone and set up West Austria. America is by then fully in Cold War mode and would support a second unification of West Germany and West Austria to make a sturdier anti-Communist bulwark. East Austria would either be unified with East Germany or thrown in a 'Danubian' confederation with Hungary.
The rest of the Cold War would unfold much like OTL, only with both Berlin and Vienna being divided cities and sporting a Wall. When the Soviet bloc collapses, you would have the reunification of Grossdeutchsland.

In order to get more, you would have either a) to make Valkyrie successful, which is compatible with part of the OP (ITTL the most likely outcome is a de jure unconditional surrender, but de facto a conditional lenient peace with Germany accepting Allied occupation, but keeping Pomerania, Silesia, and Austria) or b) Germany is more successful in 1940-44, manages to force the Soviet Union to a compromise peace and defeats landings in Italy and France, and is only defeated by the nukes in 1946. In such a case, it could negotiate accepting surrender, but keeping Pomerania, Silesia, Austria, Sudetenland, and Danzig.