I was at an exhibition a while back and Ron Dean demonstrated his miniature RC setup in a 1 : 72 Airfix MTB, which planed very well indeed. The RC was about the size of a finger that is all of it. ESC rudder servo and rx a combined unit.
I have visiited Miniatur Wunderland and it is an excellent visit. It is very close to the Hamburgh inner harbour and there were several of the preserved ships and boats there, and loads to do, could be a great long weekend.
Roy