I dont really understand the need for more seating or boxes. With $7B TV contracts, it's not about selling tickets any more. Make your program as competitive as you can (which the current RAC does) and the money will follow. The Michigan State/Gonzaga game had over 2M viewers.
I would be totally OK with expanding the building outside of the seating area. Bathrooms, indoor ticket area, even doing building extensions behind the seating to expand the concourse and add concessions, all to be done during off season