In a large bowl, combine 2 pounds shredded cabbage and 1 teaspoon salt; toss to distribute the salt evenly. Let stand 1 hour to draw out moisture.

While the cabbage is standing, make the dressing: in a small saucepan combine 1 cup vinegar, 1/4 cup water, 2 cups sugar, and 1 teaspoon celery seed. Bring to a boil over medium-high heat and boil for 1 minute, stirring so the sugar dissolves. Remove from heat and let the dressing cool until lukewarm.

After 1 hour, drain the cabbage in a colander and squeeze out as much liquid as possible—use clean hands, a kitchen towel, or cheesecloth to press until mostly dry.

Return the drained cabbage to a bowl and add 1/2 cup shredded carrot and 1 green bell pepper, finely chopped. Toss to combine.

Pour the lukewarm dressing over the cabbage mixture and toss until everything is evenly coated.

Pack the slaw into airtight freezer-safe containers or heavy-duty freezer bags, leaving a little headspace for expansion. Seal, label with the date, and freeze.