I use an Igloo or Coleman for car camping. My “secret” is to make my own ice with a small tub. For drift boat float trips on the Deschutes, I made a cooler with closed-cell foam sheets that are an inch and a half in thickness. A large block ice made in a container that is just the right size for the cooler fits in the middle and generally will last for 5 days. All of the food that can be frozen is put in first and drinks are added as space becomes available. Been using this method for years. A key element for both the portable cooler and the boat is to make sure that the melting ice water drains continuously in the boat and frequently in the car cooler.