We've been using the double sleeping bag method for many years...we pile the meat up in garbage bags on a double sleeping bag (the old heavy style large bags) and put dry ice on top, and wrap it up like a giant burrito. On a two day trip, the bottom quarters are mostly frozen by the time you get home. Works well, and never had any spoilage.
I have a similar method. I bought some 2" foam and precut the panels to fit into the back of my pickup. When needed, I duct tape the cooler/box together. I use an old sleeping bag inside of the cooler. I use dry ice to cool/keep the meat. Sure a heck of lot cheaper than a Yeti, and it doesn't take up the room. (I store the panels in my garage attic in the off season.) I have traveled from NM to MN with temps close to 100 deg. When I opened up the cooler, it was comparable to opening a chest freezer. Only disclaimer I will add is DO NOT USE DRY ICE IN AN ENCLOSED SPACE. (IE an SUV) The gas can suffocate you. View attachment 9424View attachment 9425View attachment 9426View attachment 9427