Here’s a photo from my recent 250km walk from Montreal to Quebec City. I was alone, hence no-one to get a photo of me with the trailer. You can see that it was a big pack that had camping gear in it.
Much of the route was along the very wide verge used by cyclists. The road is the oldest European one in North America north of Mexico and super popular with cyclists. At times the going along was so effortless I actually had to reach back just to make sure the trailer was still there behind me!
As the temps were hot for some days (34C) was carrying lots of water and Gatorade etc, so it took some jiggling at the start to figure out the perfect balance point where to stuff the liquid. But once that was achieved, as mentioned, things worked brilliantly.