Hi DrDetroit - I also looked at an outdoor charging system and both of the ideas above were what I originally had planned!
If you look in Amazon, I found several lockable metal boxes (you could also adapt metal post / mail boxes) which you could screw to the wall.
However, I found my charging cable could stretch from underneath the garage door, to the car, so ended up plugging my brick into a socket in my garage and I cut a small gap in the door frame to accommodate my cable so allowing me to close the door with the cable running outside.
I also screwed a 'double hook' (a jacket / coat hook) onto the inside wall which holds the charger 'gun' when it's not plugged into my car.
Hope this helps
2015 GX4h in Black
Living in Scotland