Best way to transport crawfish out of state (2 nights)

Should be. Might consider putting the ice on bottom in the chest.

I took several sacks to my friend in North Alabama for a crawfish boil. I bought a cheap plastic swimming pool, cut holes in the bottom and put all the sacks in it. I covered them with a sheet for shade and poured ice on top. When the ice melted, I stopped and got more ice. This was late May and was hot as hell outside in the daytime. When I got to his house, we sat them in the shade and watered them every now and then. We didn't have any dead loss to speak of. That being said, your method with the ice chest should be good.