My daughter is a freshman at a large state university. She transferred in 33 AP hours. She is on track to graduate in 3 years with her major & 2 minors. She will need to study 15 hours a semester. She may take a summer class too while home for the summer. But that’s because I work for a university & she can take a class over the summer for free.
she may do study abroad one semester. And she also is thinking of changing one of her minors into a second major. So that will extend her time.
So, to answer your question, your child would need to take as many AP classes as possible, find a school that takes those credits toward gen eds, and know exactly the area of study.