If you pay attention Google already does alter some images or makes the pixels so low you cannot see it.  Many rural areas uses default imagery which is very crap so likely Hogwarts would only be a tiny dot you wonder what it is when trying to zoom in. 

The magic wards would not effect machines because machines will not have the urges humans have to *go away* especially since the aerial photography is out of range for the magic wards to produce any effects.   Even if the aerial photography using drones were within range they still would not stop any drones since the spells only effect human emotions.  '
Automatic drones do not think so therefore they CAN NOT have that urge to go the other way and if the onboard computer chips are well protected by the outside frame the magic EMF currents will not mess them up.
 
For fun a street view tour of Hogwarts would be exciting if they let someone with one of the Google 360 degree backpack cameras to hike around the castle taking in the pictures when no students are there such as in the summer time. 

Maybe do it two times where one visit is in the daytime and the other at night with all the lights on showing all the common rooms empty of kids and classrooms.