Feynman's IQ was reported by himself after he took a school test. I have zero doubt that if a representative sample of the population took a scientifically controlled IQ test (and everyone participated honestly, to the fullest extent of their abilities) that Feynman would have placed near the top if not at the top of the distribution. His incredible memory, ability (and desire) to track lengthy chains of logic and patterns shine through all of his own writings and the writings about him.

"IQ score" is meaningless; "aggregate performance on tests concerning memory, logic, and patterns" is not. Do you really think that Feynman had a middling ability to perform the feats of mental acuity typically represented on an IQ test?

Perhaps I should make myself clear; rather than "IQ", I'll say "performance relative to other humans on arbitrary tests of memory, logic, and patterns". The raw scores on these tests don't mean much, and high performance on these tests does not guarantee success in physics; but prior success in physics almost certainly guarantees high performance on these tests.

Did you read the article? It is quite literally the story of a highly-motivated, creative, perseverant individual who did not have the innate ability to deal with the high-concept logical models presented in his PhD program that his advisor and other students did. Who cares about an "IQ score"? If you subjected him and the other students to a battery of mental processing tests, you'd find that his performance was worse relative to theirs.