The college cannot host the event and third-party organizations (such as Ray Compton's group that has hosted the days at Lucas Oil Stadium and some HSBB daily shootouts at Gainbridge Fieldhouse and the Indiana Farmers Coliseum) are also not allowed to rent college-owned facilities, as it's seen as giving a recruiting advantage.
However, a state association like the IHSAA *can* rent out a college facility. It happens very frequently - the IHSAA used Indiana State's arena for the girls basketball State Finals for a few years. It also uses Worthen Arena at Ball State for the gymnastics finals, IU's track, Purdue's softball stadium and IUPUI's swimming pool for their respective State Finals.
It won't happen for a neutral semistate, because the rental costs are too high. But the idea of using larger high school facilities might work.