Obviously it's difficult making assumptions from two photos. I installed professionally for a few years.
Here's what I would do.
If you dont want to cut drywall, drill through framing and repair then you really only have one choice.
Run conduit from the attic, BEHIND the brick ledge at the corner where the siding meets the brick. Paint it to match and you'll never notice it and who the hell cares anyway. Look at your huge electrical box on that side of the house.
At the bottom, drill through and into the garage. Preferrebly have an LB at that 90 into the garage.
Once in the garage, run the conduit or none along the ceiling front corner and drill out to where you want the cameras.
It really really helps having a friend who's comfortable doing these things or better yet have a contractor do the drilling and you can run the conduit and wire and seal it back up.
For the front porch, ah shit. That's just gonna suck if you again don't want to cut drywall, drill and repair. I'd honestly do something along the same lines and paint the conduit to match the brick. Then, maybe do something decorative to hide it if it's a major concern.
Here's a quick drawing that helps illiterate what im trying to explain.
While your running two cameras outside the garage, I'd install one inside the garage. Might as well.