Axis/Vegas mirrors do not fold flat--they are fixed.
The best you could do would be loosen the set screws and turn them parallel to the coach.
Keep in mind the front of the Axis/Vegas is tapered so that the mirrors may not stick out as much as you think. (The RV by itself is only 94 inches wide, see here:
https://www.thormotorcoach.com/vegas/specs/ -- not sure where you're getting 128 inches?)