The university housing division doesn’t need to sue you, they can just add it to your bill and then hold your transcripts hostage.
There shouldn’t be a problem to find someone to take one of the rooms. Is the off campus apt. a single, a room in an apartment, run by/in conjunction with the school (i.e., does one need to be a student?)? Many of the schools place students in these off campus apt and they really are only renting their room. I know at FSU the students can be from FSU or the community college or FAMU.
You need to go talk to someone at the school. Usually housing is so in demand they don’t hold you to it.