If you use 2" or even 4" PVC for the bottom frame, it will slide along easily. If you put a 3 way connector at one corner, then you can fill it with water for more stability from tipping over. I would still use wood for the cross braces for rigidity. If you use PVC, then in a high wind, it might flex a lot more than you want it to!
I am only using 2 panels for my coop, and I made the side pieces on the bottom about a foot longer on the back end and trimmed them like sled runners. I have mine on uneven ground with long grass and it's not too hard to pull. I move it up about 10 feet each time. Once the chicks get old enough to not need the heat at night, I will probably move it farther out across the yard (where the extension cord won't reach)
I am planning to make another enclosure soon for my iguanas outdoor, warm weather house. I will use a single cattle panel and make it on a 3 or 4 ft base, so it will have a smaller footprint, but be a lot taller.