We take some cubed ice, but just for the beverages. I fill gallon milk jugs with water and freeze them and they keep the meat plant cold until we get back home. We may pour some cubed ice on top of them if it get real warm. Also keep the cooler in ther shade as much as possible and we cover them with moving plankets.
If I am after an antelope I'll take my 165 qt cooler and fill it with frozen milk jugs. Once I get to where I am going to hunt that cooler will never get opened unless we need to put some meat inside it. It is surprising at how long that frozen water will last that way. The longest that I have tested it is about 6 days with still enough ice not to have to worry. Now the cooler that has the beverages in it, well that ice goes fast.
One of the most important components of deciphering a new hunting area is distinguishing between the summer and winter ranges for the game that you plan to pursue. Without knowing this you cannot make reliable assumptions about where the game will be come opening day. Knowing these areas will allow you to take the current weather (as well as the past couple weeks) and apply that to the landscape and make an educated guess as to where you might find that big buck or bull.
There are a couple ways...