[SWHouston]

I have a Doggy Door, and mine have access to the outside when they need.
BUT, its not for everyone, specially those with very small animals.

I'd definitely suggest the "expanded" area inside !

When conditions (rain/weather) make outside trips troubling, I have a
Utility Room, which is fairly large, and the door can be closed to the
rest of the house. I haven't used that in quite a while, since both of
mine are reliably "houseworthy". (potty/electric cords/all)