Act 1 areas are permanently closed for access without a warning or a time grace period.
Game is linear and shuts the door unexpectedly and prohibits visiting areas where previously player has been without any restriction.
Larian Studios , Can you allow and permit the travel to all areas when player opens the waypoint ?
Also the rest restriction in some areas and prohibition to use camps while in the area or before an event. And it not possible to prepare for evacuation without knowing all things in advance. For further info , see the bug ticket for the chests in the Camp area.