I think that Zhdanov, and not Molotov, would have been the most likely successor of Stalin in 1945. He enjoyed a better power position within the Party, had a better position to make a deal with the Army (he made Leningrad resist the worst siege in modern history, after all, and he was a strong proponent of expansion towards West), and would have gained the hardliners support as well as Molotov, not to mention that he had his proteges from the Leningrad group, including Kuznestov who was a possible replacement for Beria. Molotov could only count on Voroshilov and probably Kaganovich, Malenkov and Khruchshev being lesser players in 1945. Beria is a goer anyways : hated by the Army, far too dangerous for the others.
Actually, Zhdanov wouldn't have been funnier than Viatcheslav, and I strongly suspect that, among other things, Finland would have become a Soviet satellite very soon. After 1947, assuming that Zhdanov dies even if not encouraged in his alcoholism by Stalin, Molotov could make a comeback, although the young members of the Leningrad group might as well seize power and purge the old guard.