Here is a motorized RC platform that lets you move your trailer without having to break a sweat. The Trailer Valet RVR can be operated from up to 40 feet away. It has treads to go over difficult terrains. The RVR is available in 3 models ranging from 3,500 lbs, 5,500 lbs, and up to 9,000 lbs.
The rechargeable battery runs for up to 30 minutes. You can find out more about it here.