I went through this last spring. Towed a Response from Orlando back to NH. From my research, none of the rental car companies would okay towing a trailer, but my insurance company would cover me when towing. Pretty much every large SUV comes from the factory with a receiver. Bought a one way ticket on Southwest. Checked bag is included, so I put my hitch, and an assortment of tools in the suitcase. Flew in, took a taxi to the rental company, picked up a couple extra trailer rims/tires (I knew the trailer was in rough shape), picked up the boat, and drove 1,300 miles in 23 hours. Fun adventure for sure. PM me if you need more info.
And I tried U-Ship. I've heard stories about people getting boats towed similar distances for less than $2K. Took three weeks to get my first quote for close to $5,000. Second one was even more. I spent under $1,000 and had a fun time doing it.