So virtually every school with a decent sized gym tries to keep it rented outside the term. And they much prefer long term rentals. So a group like the IJA is less desirable than a kids program, or basketball camp that can run all summer. Likewise, they try to keep the residences full with specialty programs. Basically, they'll rent to the IJA if nothing better comes along.
Casinos seem to be willing to give away rooms and juggling spaces just to get people in the door.
Their bet is that you'll gamble away more money than it costs them to supply the space. As long as enough people lose, the IJA will be welcome. The cost of a cheap room is putting up with a 24 hour attempt to separate you from your money. My impression of the Montreal fest was that there are a LOT of IJA members whose attendence at the festival is based on what there is for their families to do in the area. Their concern is less about cost and more about keeping the non-jugglers happy.