In our community, a Chinese girl who is top 10 swimer in the U.S. and admitted by MIT. I don't know her GPA.
My daughter who has same situition, she has 4 AP, plus extra online calculator. So far, she kept all above 95% in all but she almost sleeps 1 ~ 2 at night. No way to drop a course. Only one direction. The option is drop swim.