SharePoint Online as Intranet
Many administrators ask the same question "Can we have an instance of SharePoint Online intranet"?
We all know that SharePoint Online is a PaaS (platform as a service), and hence requires access internet to get all functionalities.
Now, virtually, it is not possible to set up intranet as an internet connection is always required. But, we can restrict usage of SharePoint Online based on IPs and network locations. In this way, you have the ability to restrict the access to SharePoint Online from some selected locations.
See the full demonstration in the video below:
Hope this will help you out.