Venue regrets - seating

I’m 4 weeks away from my wedding date and I’m having major regrets about my venue. I’m doing a station style reception. My venue is mostly indoor with a nice outdoor terrace facing the river. I have 165 guests and I just found out from my venue that they can only seat 130 guests at tables inside. The owner had told me previously that they could do full seating but the on-site coordinator disagrees (he has been the most stressful part of my planning process). They do have some small tables outside that will seat about 20 guests. I could probably rent a couple more tables to go outside. My concern is that guests might feel left out by sitting outside plus it’s late September in southern Louisiana heat. Should I do open seating with a few reserved tables inside? or assign all the tables and risk ticking off the guests who have to sit outside. There are also a few benches/couches inside where the “outside” guests could sit but they aren’t at tables. I wish I could change the venue completely but it’s too late for that. Any suggestions?