Have you considered a dog ramp?

MaxWorks 50524 61" Portable Folding Pet Ramp, Black https://www.amazon.com/dp/B08MFT3JRT/ref=cm_sw_r_cp_api_i_8CA0Q9ED1MPEJ87G7H4R

You could slide it down the ramp with minimal effort. They are lighter and meant to fit in a vehicle.

I would consider a tow hitch and an aluminum tray with a ramp a better option.