Keeping your food and drinks cold is always a challenge. Coolers run from your basic cheap styrofoam ones to the top of the line Yeti's. As far as keeping ice in a cooler each has holding times better than others. However for the price of a Yeti I can buy an awful lot of ice.
We've had a Coleman cooler for almost as long as we've owned the pop up. It's basic and cheap. Yes it doesn't keep ice for days on end like an expensive cooler, but I've found a couple things to help that.
When you buy ice from the store or a machine the first thing to realize is the tempertures are kept at just the freezing point to minimize their electric costs. If possible buy your ice a few days ahead and drop it in your home freezer. The ice will freeze colder and last a bit longer.
Large jugs of ice will melt slower than cubes. If you can keep a few jugs from milk or juice, clean them out good then fill with water and freeze. A couple of these in your cooler will last a lot longer than cubes, and you have spare water when it thaws.
Another item we've found that helps is a cooler cover. A company called PopUpGizmos sells a cooler cover, and since we've owned one find it really does keep ice longer.
A camping friend found that using a thin piece of styrofoam on top of the ice in the cooler also helps keep ice longer. That also makes a nice shelf to keep things away from sitting directly on the ice.
Another issue with coolers is critters getting in. Raccoons love to feast on your food, and are very good at opening many coolers. With our Coleman cooler I found that the handles also make a great locking device. The handles stick up just far enough to fit a broom handle under them, so I run the broom across the top. The handles keep the cooler locked, and there isn't a raccoon that can break in. We know, it's been tested by several.