Adelaide has a compact city centre, and there are many hotels in walking distance from University of Adelaide’s North Terrace campus, including (from less to more expensive) the Grosvenor, Ibis, Rockford, Hotel Richmond, Majestic Rooftop, Playford.
For groups, Airbnb can also be a good option. We did not make a block booking. Shopping around may get you the best deals.
North terrace campus – the info regarding locations can be found under the question mark in the attached PDF.