I'm sure you could still hire it out to all sorts of classes, My DD's dance school has 2 big rooms and a ouple of smaller ones, they probably need the big rooms for exams as they have set pieces to do that wouldn't fit in smaller rooms.
But all sorts of other rental opportunities. Especially if you can supply child size chairs from downstairs, floor mats etc. Or even charge for a crech while parents attend classes.
Babysigning, tumble tots, dog obedience etc.