Can Custom Pages be set to publicly available, when the Community itself is private?

Interesting question and really great idea for a use case. I’m not sure the answer. My guess is no.

However, a solution could be having a “hybrid” community with Public visibility and Private categories. However, some things like User Profiles, Events, and Product Updates are fully visible in Public community setting. 

I talked about this on a webinar with Insided in October. Recording link and more of my thoughts in the answer to this post: 

@DannyPancratz Thank you for your reply. A hybrid community is not an option for our use case. I think we need to find another solution for an info page.

Hi ​@mmue , we are looking into a very similar scenario, and I am thus wondering if you found a solution to your issue?

Sadly, we didn’t find a suitable solution using the Gainsight Software. We had the Landing page with all the Info put on our main Homepage and then forward to the Community registration page.

Ah that's a shame indeed. Looking at the date of your post, I assume this had been in place for a year already. How has it been? Do you think it impacts the user experience? 

We only had this landing page run for about a couple of months after the launch of the community. We didn’t get any responses on the process, so it seemed to have worked out for our community.