Everyone’s situation is different. If you start with a lot of AP credit it is certainly doable. My daughter will graduate this June and she spent two quarters studying abroad in South Korea her Junior year. She will graduate with a CPE degree and will start with Apple next September after two consecutive internships. A good friend of mine has a daughter that will take an extra semester to graduate from Carnegie Mellon, since that school accepted very few of her IB credits. A semester at that school is more expensive than a full year at CalPoly.