If only life were so simple.
After wasting 27 years threading needles all over the country with 75-foot-long 18-wheelers, I feel inclined to believe that Driver Skill would be a limiting factor long before Steering Geometry could come into play.
And what do we suppose might happen to the scientific turn radius of a bus when the tires sink eight inches into the mud of this camp-ground goat trail?
While I happily welcome you to the forum, Anthony, I can only suggest you buy the big bus and use it for 20,000 or 30,000 miles on a wide range of roads and driveways. Then, perhaps, you will have a fair shot at answering the question.
In slightly better news....
That bus -- a flat-nose front-engine layout -- has a surprisingly short wheelbase for its overall length. Long front overhang, and enormously long rear overhang. So the tires can turn in a relatively tight space for the imposing bulk of the vehicle.
The body -- front and rear bumpers, more or less literally -- would swing outside the edges of the road and might collide with trees and whatnot.
There are simply too many variables for your question to be answerable.