when I was playing solo with backing tracks, I couldn't risk multiple trips because I didn't have anybody to watch what was left while I was gone with the first load. So I bought a rock n roller cart with pneumatic tires (recommended). That enabled me to move everything in and out in one trip. They come in different sizes, and I think bigger is better. Even with a fairly large cart, you need an organized method of stacking your gear to make it all fit. The biggest constraint is whether your vehicle has enough space to hold all your gear AND the cart. Even though they fold up, they still take up quite a bit of space due to the wheels

https://www.dropbox.com/sh/ey71h8ep047758h/AAC12jNM0Hz9Q8zsh5iDeqNHa?dl=0