I’ve had better luck with ice bags vs dry ice. I leave it in the bags instead of spreading it out over the meat because it will last longer as one big lump. If you do use ice, leave the drain plugs to the rear. Then if you need to drain some water you can slide the cooler aft a bit and drain it without having to unpack stuff to turn it around.
That’s worked well for me on a dozen trips traveling from western Colorado to Mississippi.
