i am also doing this 🙂. i am visiting my top 2 choices again and this time bringing part of my family, since i didn't want them tagging along to the schools when i interviewed 😳. i called the schools and told them i wanted to come up again and they were both fine with it. i would definitely call to give them a heads up. depending on the school, they may take the initiative to help you set up an appointment with the dean of admissions or someone else who can answer any questions and maybe give your family a tour.
i also want to go back to see the towns b/c i didn't get to look at anything before when i interviewed (airport--->hotel---->interiew---->airport)