That's pretty much the idea, but I'd like to hide from the public the knowledge that there is a private side to the site, just for security reasons. So there won't be a "Login" button or "Board Portal" link on the public-facing site.For your meals on wheels site, depending on what you are using for a web development tool, you could create a login that gives certain users access to additional pages. Those without a login in will only be able to see the public content.
We're using WordPress along with Elementor to implement the main site. I'll be talking with the developer about how to implement the private side of it. I'll be taking over as admin after he has finished the initial implementation.