Last Month, I pulled a 232 Gulfstream from San Antonio to Tacoma... 5 day, 4600 mile round trip with a buddy trading off driving and sleeping.
Lowest bid on U-ship was $3400.00 so I drove down and pulled it back myself for less than half that price in fuel. Drove down through Idaho, Utah, New Mexico. Quickly decided that was not the route to come home with a large boat in tow.
I came home on Interstate 10 to CA, 215, 15, 395?, north to Bakersfield, then north on 99 to I5. That is the way I should have gone down there. I would not recommend taking hwy99 with a large boat in tow... too many short on ramps on that road. I5 would have been a better choice I believe.
If you do this, bring a full set of spare bearings, make sure the tires and brakes on the trailer are in good shape before heading out.
It took 2 full days of cleaning to get the bugs and road grime off the boat after I got it home.
If I had to do it over again, I'd take a couple more days and get a bit of real sleep. Saved a bunch of coin over having a shipper move it though.
Good luck.
steve