One of my kids skipped a year and also did significant subject acceleration in two areas (4-5 years). We were lucky to live in an area that has selective entry MS and HS math/science/CS programs that offer an easy way to take a faster track, including a significant number of college-level courses taught in-house. He could take advanced classes with his age peers -- and he was not the youngest in his grade. He chose not to go over to the flagship (a short bus ride away) for courses, preferring to be involved with his ECs and friends at HS. Best of both worlds. He would have withered on the vine at our local HS.
He also came home at night and taught himself most of a BS in CS.