I had a Tadi Brothers wireless camera on my
Escape 17B, and ran a cable from the camera to the front of the trailer, where I placed the transmitter. Never had a drop out problem.
I currently have an Escape 21 with the factory installed Rear View Safety camera, a model that has a built in transmitter in the camera's case. I was skeptical since the distance was much longer than with the previous system, but I've never had the video dropout. At times, the refresh rate seems to slow down, but never enough to be a problem.
If the antenna you referenced will work with your camera, moving it to the front of the trailer should make a good improvement. I've found Tadi Brothers good to work with - if it doesn't do the trick I suspect you would be able to return it.