What exactly is Wilsonianism and how did it differ from OTL US foreign policy after World War II? Much of the rhetoric during the Cold War was very much in the "making the world safe for democracy" vein. Moreover, even the policies, though obviously they had to be adjusted to new realities, showed considerable continuity with Wilson's.
Wilson supported an organization of nations--and so did the US after World War II.
True, the US after World War II did not view the UN as a substitute for alliances like NATO. But neither did Wilson think that the League precluded a treaty to guarantee France against future German aggression:
https://en.wikipedia.org/wiki/Treaty_of_Guarantee_(proposed)
True, the US after World War II devoted much energy to opposing Russian Communism--but of course so did Wilson. In fact, he actually sent troops there, which the Cold War presidents did not.
True, the US after World War II was worried about radicalism in Latin America--but it did not actually intervene there nearly as much as Wilson did.
For an argument that America's Cold War policy was fundamentally "Wilsonian," see
http://www.h-net.org/reviews/showrev.php?id=4239