Most of the largest hotels are connected via a network of tunnels and enclosed walkways. You can get all over downtown Indy without even setting foot outside. One big, (sterile?) connected bubble.
I would guess the convention center would be set up with multiple floors, along with Banker's Life and Lucas Oil Stadium, at least for the early rounds. It wouldn't be hard to have 4-6 games going on simultaneously.
Why would they want to have more than the traditional four