I drive from SC to all across the west every year for elk/mule deer/or whatever tag. I take a 160qt, 120qt and a 50-60 qt when I go elk hunting. All 3 are igloo or coleman coolers. The 160 and 120 are for meat and the 60 is for a cape if things go really really well, lol. I freeze different size jugs in my chest freezer before leaving. Primarily 1/2 gallon milk jugs, but there are some gatorade bottles and other random jugs (some big, some small). I then fill up the 160qt cooler with these jugs the morning/day I leave. I pour loose ice over the top of all the jugs and fill the entire cooler until its packed full. I then lay a towel inside the cooler over the top of the ice and tuck it in all the way around as an insulator. The ice and jugs will all freeze together. I put the cooler in the back of the truck under the camper shell or in the backseat so its not in the sun. If it has to go in the back of the truck wrap a couple blankets around it or something like that so it's not in the sun. Don't open the cooler until you have meat to put in it even to check the ice level. Keep it closed. Tape it if you have to. Use a different cooler for drinks and food on the ride out there. There will still be plenty of ice whenever you kill your elk. Some ice will melt, but a plenty will still be frozen even 10 or 12 days after packing the cooler even on warm days. I always keep the cooler in the shade if all possible. After I get my bull I split the meat up between the 2 coolers and pack all the milk jugs around it. I'll check it once or twice on the drive home and stop at gas stations for a couple bags of ice to put on top as needed. Once you open the cooler and put the meat in the frozen jugs will melt alot faster, but stopping a couple times during a 25-28hr drive home isn't a big deal. When I get home the meat is always very cold to the touch and Ive never lost an ounce of meat or had a cape spoil (hair slip).