College kid looking for a mobile dorm...
Interesting idea. A few things to keep in mind though.
1) What size is your truck? 1/2 ton, 3/4 ton or other? The towing capability of the truck will have a major impact on what you can tow.
2) Where will you park it? No college I know of has parking big enough or long enough to put a RV in. You will probably have to go 'outside' of town, and then have to worry about commuting to school. Which leads to
3) How are you going to hook it up? If the place you park it does not have a water source, electricity source and a dump outlet, you won't have refridgerator, shower, microwave, AC or even lights and toilet after a few days because your batteries will be dead and your fresh water tank empty and your sewer tanks full. There are many places which can take care of these needs, but they cost money, so you need to find a place within a reasonable distance, and figure the cost into your computations on what to do.
4) Phone? Internet? Cable TV? All of these are often harder to get in a RV. And sometimes more expensive.
5) 15 to 21 feet (times 6 to 8 feet wide) is a pretty small space to live in for a whole semester. Are you sure you can survive it?