This is one of the reasons I have a 22 foot truck (full crew cab with 8 foot bed).
We never have had a reason to open the TM between departure from home until arrival at camp, 4 to 5 hours later.
When we leave home the TM fridge is usually chilled and full of non perishable items, such as the cold beverage of my choice. This is frequently loaded a week in advance.
Perishable items are carried in a Coleman 12 volt cooler inside the truck. We get ice for the ice chest on the way, near our destination.
Upon arrival in camp, the cold beverages are moved from the TM fridge to the ice chest, the perishable items are moved form the 12volt cooler into the TM fridge. the 12 volt cooler will not be used again until we go home, using the same procedure, except that the TM fridge is empty and the door left open on the click for ventilation with a towel inside to catch any moisture..