Miami offers several pre-orientation programs (such as U-Lead) that allow your child to move in several days earlier, avoiding the craziness of move-in day, and more importantly provides the opportunity to meet other freshmen in a structured program. It will also highly increase your chance of finding a hotel room in Oxford as opposed to 30 to 40 minutes away. Whether you do a pre-orientation program or arrive on move-in day, one night is enough since MU will keep your freshman busy. Here is a link to U-Lead, you may want to call admissions to learn about other options:
http://miamioh.edu/student-life/student-leadership/student-opportunities/retreats-conferences/ulead/index.html