There are several studies that show that IQ correlates with income, at least at the extremes. However the studies I've seen found no correlations between IQ and overall happiness or contentment with how their life turned out.
Someone in a gulag would have low life satisfaction.
The original lottery winners vs accident victim study attempted to measure the long term state: https://www.talenteck.com/academic/Brickman-Coates-Janoff-19...
That study isn't the final word though. Other studies have found that winning the lottery increases life satisfaction, while still others have found that they don't.