Network Solution for Small Business - Router Options for 300+ Simultaneous Clients

We have a small business that has 20 guest rooms, a tavern, and a banquet hall for weddings.
We switched ISPs and the new one is far better service, with up to 800x800 symmetrical fiber, but the router is incredibly residential and often is overload when we have high volume of users.

I am looking for a router solution to work with our 10 access points connected through a unmanaged Netgear gigabit switch to handle the volume. I am also open to using multiple routers to handle the load (as long as the single modem from the ISP doesn't become a bottleneck).

Generally the high volume is about 300+ clients per hour between all the entities, Sonos speakers, and our staff, about 1-2 days a week.
The rest of the week the highest volume is about 100 clients per hour during peak operations in the Tavern.
I'm looking for some network solutions that will help reduce network overload. Thank you in advance for any tips.