Crystalized IQ by highest degree (General Social Survey)
A while back someone claiming to have an IQ of about 65 posted to this subreddit saying that not only had he finished HS, but that he wanted to go to college. Many users were supportive, though there was also plenty of skepticism too - not only that OP could actually accomplish this goal, but that his IQ was actually 65 to begin with, as some people argued it was nearly impossible for him to have completed HS with such a low IQ (or to even write a post with relatively normal English), so his results must have been flukes.
I was curious to know how many people in this IQ range actually manage to finish HS and college, so I used data from the General Social Survey to help answer this question, and took the opportunity to also plot the IQ distribution by education level. Specifically, I used the "wordsum" variable (the score participants got in a short vocabulary test) as I've seen some studies use this variable to estimate IQ before. Vocabulary is one of the most g-loaded tests so that makes sense, though due to its limited scope, small number of questions, and difficulty in measuring higher IQs as you can see in the graphs above, along with with fact that I don't control for other relevant variables like age or parental income, these should not be considered robust or definitive indications of anything, only tentative estimates made out of curiosity.
223 participants had an IQ score under 70 (raw score of 0 or 1), of whom 96 (43%) completed HS, and another 24 (10.8%) went on to get a degree. So although many of this subreddit's users were skeptical of the OP, completing HS with an IQ of 65 is not impossible, and neither is it to complete college - though the OP will definitely be fighting an uphill battle.
As for the average IQ by education, unsurprisingly they were positively correlated, though because scores were truncated at ~130 IQ the averages calculated for both undergrads and postgrads are likely underestimates.
If anyone reading this had their curiosity piqued by this post, just know that you can expand on it by analyzing some of the other variables in the GSS, specifically those in the Knowledge and Science sections (e.g., bigbang, electron, odds1, etc.), as they also often involve crystalized intelligence. I won't be spending any more time on this myself because I actually have a test tomorrow night and I haven't even started studying yet lol.