Here is the link to book at the hostel. Booking code "IAIDO26".
https://uoguelph.starrezhousing.com/StarRezConferenceX/5B839B1D/108/1598/Book_Now-Group_Selection?GroupCode=IAIDO26&HadEmptyContext=True
To contact the hostel serrvices email accommodations@uoguelph.ca.
Note that Gordon Hall is the old Days Inn hotel. It is an option along with the dorms and the townhouses.