My trailer is 8 ft wide +, I'll admit I am no good at backing. However, I can get it where I want it, without dinging anything. The other day on the trip to Lake Charles, I took the trailer to the dump station and brought it back to the site. I had left the chocks in place and I managed to get it back in the chocks on the second try.
I store mine in my shop, and back it thru a 12w x 14h door, it usually takes a few tries to get it where I want it, which is over to one side somewhat.
The side door is 10w x10h and I back the truck thru it with the mirrors flipped out, leaving me only 2 to 3 inches on each side. Its easier to do when it is dark and the lights are on inside. I also had to make sure It fit between the lift posts when I backed in.
When I was reworking the roof on the Thor trailer I had a buyer coming for the Motorhome. As rain was projected, I needed the motorhome inside for the buyer to look it over. The day before I took the Thor with the unfinished roof (thus no A/C) and backed it thru the side door and into the lift.
At work, I went most of my 30+ years avoiding driving the tug moving airplanes. Toward the end I was forced to do it a couple of times, which I did without any real issues.
The shorter a trailer is, the harder it is to back. My 5x10 utility trailer is extremely difficult to back, made harder due to the manual steering on my Ford Ranger.
Charles