The length of time you can keep a bag of ice in the freezer depends on various factors, such as the temperature of the freezer, the quality of the bag, and the initial state of the ice. In general, if the freezer is set at 0 degrees Fahrenheit (-18 degrees Celsius) or below, and the bag of ice is properly sealed, it should stay frozen indefinitely.
However, ice can still deteriorate over time due to a process called sublimation, where it slowly turns from a solid into a gas without melting into a liquid first. This process can cause the ice cubes to shrink in size and lose their freshness and quality. The rate of sublimation is influenced by factors like air circulation and the humidity level within the freezer.
If you want to maintain the quality of the ice cubes for an extended period, it's recommended to use them within a few months. For drinks and general cooling purposes, ice cubes that have been stored for several months should still be safe to use, although they may have lost some of their original taste and quality.