Hayden Homes Amphitheater question

Hello, I didn't plan correctly it seems. I'm wondering if anyone has some last min advice. I got concert tickets for me and my dad, he has a recent hip replacement and currently using a walker. I called in advance and they said we'd be permitted to buy 2 tickets in the ADA section--- now I'm realizing there's this some chair drama at this venue, and it seems I'm no longer allowed to rent a chair, and that I cannot bring a chair. Does anyone know if the ADA section has any separate rules, like if my dad is not in a wheelchair, but cannot stand the whole time would they let me bring him a chair? Or do you think we can rent chairs at the actual venue or do they all have to be rented before hand. Thanks for any help... I'll call in the morning, but they are closed for today and I'm panicking if we should even make the trip to Bend.