Audiovisual technology has come a long way in recent years; so much so that today you can turn your event into a live television program and broadcast it on a chosen channel to your entire audience.
This way, you eliminate the need for the public to attend the event in person. As well as being able to follow the event online through platforms such as Zoom or Youtube (amongst others), your audience will be able to ask questions, register, etc.
Even if a member cannot attend the event in person, he or she can take part remotely , interacting face-to-face in real time with the other attendees.