I know exactly what you are talking about. Really dangerous when my wife is not with me. These intersections are a rare occurrence but are still a real pain. When I encountered one without her I would get out of the drivers seat and move to the side window where I could see if there was any traffic coming. I would then quickly hop back in the drivers seat and quickly mve through the intersection. Far from the best choice but really the only option I had at the time. An additional camera would be great. You could run it to the auxiliary input on the monitor.
2014 Fleetwood Bounder 35k