Definitely do not duplicate your app! Quick Base access control is stellar and flexible and bullet proof.
if you only will have a couple of Regions, I would setup a Role for each Region and though the Custom Role Permissions limit access to only view the appropriate Region. Note that you probably have some kind of hierarchical structure with region being at the top, and you can lookup the region to any child records and also limit access to any Child records too - like Projects for a Region and tasks for projects for a Region and tasks
Here is some help on Roles
https://help.quickbase.com/user-assistance/cs/cs_about_roles.html 
