I recommend freezing the blueberries in one-quart bags.
A gallon of berries is a lot to use in one throw, but a quart of berries is just about right for a small pie, batch of muffins or breakfast-type use.
I froze them on a cookie sheet before packing them in the bag so I can scoop out a cup or so at a time. They’re not stuck together. I doubt they last more than a few weeks.