Most students will want to move off campus either sophmore or junior year. This gives them the option to have more freedom. Not too much is going on around campus, so it's good be closer to some sort of civilization.
It's not too hard to find off-campus housing. The area around SLU is not heavily populated, and there are always places to rent. There are plenty of apartment complexes around the area. You most likely will not find anything within walking distance to campus, but there are places where a lot of students tend to stay, so it won't be too difficult to find a ride. Most of the apartments and houses in the area are cheap and not in too bad of shape. Living off campus is a must as you get older. It is also much cheaper to live off campus than on campus, everything considered.