Meat back at the car/trailhead

[5MilesBack]

I'll stick to dry ice which Im more familiar with

Back in the early 90's when I was stationed in CA I drove back from CO with a quartered muley in the cooler. It was a HOT fall and still in the upper 90's through Nevada, so I figured dry ice would be good insurance. I layered cardboard boxes over the meat and then put the dry ice on top of the cardboard inside my cooler tray. After 24+ hours of driving and sleeping, got back and the deer was frozen solid. I've been pretty leery of using dry ice ever since except on meat that I want frozen.

 

[ElkNut1]

I'm pretty much a cooler & ice guy, no issues with it when maintained. Don't fix it if not broke! (grin)

ElkNut/Paul

 

[archer wapiti]

I buy the 2 1/2 gal. drinking water jugs from the grocery store and freeze them after draining out a little to add some expansion room. I've also read that you can line your cooler with the thin Reflectix duct insulation that takes minimal room (I'm gonna try it this year.) I also made my own redneck Yeti using thin plywood that I got free, and lined it with 2-inch rigid foam sized to fit my older Igloo marine cooler, filled with the 2 1/2 gal. ice jugs. I also cover it with an old sleeping bag and only get in it occasionally when the ice in my other coolers get low and keep the windows cracked to minimize heat buildup. I spent 22 days in WY in 2015 and it still had over 50% ice left. The negative is that it takes up a lot of room in the back of the Suburban and is too heavy to move around but it did work great and I plan to use it again this year.

Leaving room for expansion is key!
I find that milk jug material isn't very durable compared to 2L bottle material, so use 2L instead. The only problem is that I don't drink that crap, so have to buy club soda.

But back to the OP question... If you can find a well-shaded spot within a half mile or so of the trailhead, I'd be inclined to hang it there for a couple days if it's properly bagged in game bags and staying dry. As long as the sun's rays aren't hitting it, those 40 degree nights are going to cool it down and it won't warm back up. If you do transfer it into ice, I'd do it in the morning after it has had all night to cool.