Connect should be able to handle everyone you have licensing to accommodate.
Do you have any specific needs like everyone at a single location but on separate computers/devices or everyone on live VoIP? Those can present issues, but without knowing the specifics of what you are trying to accomplish it's hard to say where your pain points will be.
This is what I find in my licensing, which is why I'm confused. 100 or unlimited. I plan on having everyone log in via computer and listen using headphones, but am providing a call in number in case of issues with connection. The audience will ask questions via message. No two way communication.
Meeting Peak Concurrent Users: Unlimited (Soft Limit: Unlimited) Concurrent Users Per Meeting: 100 (Soft Limit: 100)
So you have the Named Host licensing model. This means members of the Meeting Host group can create and run meeting rooms that hold up to 100 attendees. The other license is unlimited because you are not using the licensing model. Each Meeting Host group member can run one meeting at a time.
After 100 people are in the room, additional users will start seeing a notification of your licensing limitation being reached.