Freezer Cucumber Pickles

Rinse ten 2-cup plastic containers and lids with boiling water. Dry thoroughly. Divide cucumbers, onions, salt and water between two large bowls. Let stand at room temperature 2 hours. Do not drain., Add 2 cups sugar and 1 cup vinegar to each bowl; stir until sugar is dissolved. Transfer to prepared containers, leaving 1-in. headspace for expansion; freeze up to 6 months., Thaw pickles in refrigerator 8 hours before using. Serve within 2 weeks after thawing.