The problem is that by September 1944 the Red Army is practically in every country it would occupy anyway. It's hard to see the Western Allies doing so much better that by that time they are in Eastern Europe as well.
Yugoslavia is going to be dominated by Tito.
Bulgaria and Romania are going to have the Red Army all over it.
Hungary and Poland are likely to be occupied before the Western Allies can do anything.
That leaves Czechoslovakia, and the Czechs are in a very strange situation. First, almost alone of the Eastern European countries, it is not anti-Soviet. Second, given the history up to Munich, the Czechs know they can't count on Western Europe to help them because of the geography. That means they must rely on the goodwill of the Soviet Union. People tend to read too much of the initial postwar politics through Cold War lenses. In 1945-1946, the main issue was not the US vs USSR, but "how they hell can I guarantee Germany won't invade my country for the third time?" I believe the Red Army had already left Czechoslovakia by the time the government walked away from the Marshall Plan, and the Prague coup was done internally by Czech Communists and not through the Soviets. None of these dynamics change with a greater Western Allied advance in 1944.
The only way I see non-Communist governments in Eastern Europe is if the Allies have a more successful Torch in 1942 or invasion of Italy in 1943 that allows some troops to be diverted into the Balkans by 1943 (probably because Churchill insists on it). If so, then Bulgaria, Yugoslavia, and perhaps Romania come into play. Bulgaria and Romania may come into some sort of workable democracy, but Yugoslavia probably descends into a terrible civil war afterwards. But the level of competence, experience, and intitiative for that are probably beyond the Western Allies at that point.