If all of the characters in your VG are yours and no one else has any characters in the group, then you would end up with a full VG roster of characters who cannot access the base. (And each time the current leader of your group switches alignment, that rank will be shifted to another character who is eligible to hold the title. I don't know for certain what happens if all of them are ineligible, but I would assume it just sits on the last character who switched.) If you ever switch a character back to the red side, they would then be able to pay rent, open the base again, and access anything you left in there when everyone switched to blue side.