First, save half your money by checking out Rtic.
I've not done the trip you're asking about, but just for thought. I took an elk frozen from Oregon to California when I first moved down there. Meat was frozen before leaving, I put a piece of foam under the boxes, put blocks of ice around them, and completely covered the pile with sleeping bag, coat, etc. Not only was the meat still frozen after twelve hours on the road, but very little ice had melted.
Whatever coolers you use fill them to the top. Air sucks out the cold. Consider dry ice, insulate under and over if possible, keep out of the sun. Same as every other trick to make ice last in a cooler.
