The roof is an interesting example, since the guy using the receptacle is already up there. It would be more disruptive to have the reset button anywhere else. I agree these probably will not ever get tested.
In prisons I only saw breakers, in locked panels.
I would not want a GFCI up on the soffit, no matter what. A good place would be inside on the wall opposite the outside outlet at regular receptacle height.
In my house I have a dedicated GFCI circuit for our holiday lighting on a timer. It is next to the panel.
