Create one, single public site without enabling this on the whole tenant

Question

We would like to restrict access to our Sharepoint sites to only authenticated users (internal and external), an put one, single page with some information for those who are really lost (looking for contact, lost pw etc).
Is this possible without enabling anyonymous access on the tenant? I know that enabling this only gives the option for SharePoint admins to open a site to the public, and will not open by default (not sure, what will happen to Public groups though), but still, this site should be the exception and not the standard.

Answer 1

The option to create a public site had been deprecated a long time ago and I think it is now completely removed from SharePoint Online / Office 365. If you want to display information to anonymous visitors you would have to host it somewhere else.

https://support.microsoft.com/en-us/help/3027254/sharepoint-online-public-websites-to-be-discontinued