It depends upon how much and how fast you use ice. The freezer space with my refrigerator is not THAT big. After loading it with frozen meats and such, there's no much room for ice. We keep a cooler with us all the time so we can keep ice in it. We also have an electric cooler when we plan on longer trips to stock more cold stuff. Still, the freezer area is only so big.
We don't consume a LOT of ice, but my wife started making home brewed tea again, instead of bottled tea, and we're using it more now. When we do have ice available, I also use it a lot more too, (soft drinks). I suppose we are ice munchers!
But that's the reason campers purchase so much ice... lack of space to keep it and how fast they use it up.