I agree with Cameron, but as Aaron stated, this is really a legal matter and you're best bet would be to consult with an Attorney specializing in issues of Real Estate.
Thanks, Todd Norsted
Without signing a lease you are in a tenancy at will which means that in MN you must give one month + one day's notice to the landlord in order to terminate your arangement. I would not stop paying rent but rather give the proper notice and find another place. I hope that this helps.
Again, I am not an attorney and this should not be considered legal advice. Please consult an attorney.