Why decide on your soup now? Cabbage freezes quite well on its own. Chop some or shred some and give it a 1-2 minute blanch. A quick dry in the salad spinner and it's ready to pack into freezer bags and become something tasty later.

I found a gallon sized glass storage jar at Kroger last year that is square. It's the perfect thing, since the water-filled ziploc goes right to the edges and corners. Also, good point about the weather. Last fall, I made my first batch of kraut, and it definitely developed "le funk". But when I made it again in early spring, it was amazing.

I need to make some when the weather gets a bit cooler. We don't have central air here.
When I do quick pickles, or kraut I use a straight edge 'crock' type cookie jar and either a plate and a weight, or just a baggie with some brine in it--in case the seal breaks.
I probably need to get a dedicated crock for pickles/kraut etc. As I get "Where are the cookies" looks.

Nyah, nyah, Sam1148, beat you to it. But isn't it worth it to have multiple votes?

Here's a great source for how to make sauerkraut: http://www.wildfermentation.com/resources.php?page=sauerkraut

I wish I had lots of spare cabbage!

@sarah K: Get out of my head ;)

Make some homemade sourkruat. It's easy and tastes good. Basically, you just slice it put in layer of salt and cabbage and leave it alone. Put a baggie filled with water on the top as a weight. Skim off the 'bloom' after a couple of weeks.

Or Sauerkraut! Here's a vote for the original method of preserving the cabbage harvest. It keeps its great vitamin content, gets some lovely probiotics, keeps for ages in the fridge, and is so yummy with scrambled eggs for breakfast. And is so easy. All you need is cabbage, salt, and a non-reactive container.

Fry some onions with cumin seeds, ginger, and curry powder, then add carrots, broth, and cabbage to make a curried cabbage soup. I usually purée my soups and they keep very well in the freezer. Add a couple potatoes for a heartier soup.

I know this one freezes well
http://www.food52.com/recipes/11938_cabbage_and_kielbasa_soup

Does it need to be soup? I love making unstuffed cabbage (basically cabbage rolls with a lot less hassle) with extra cabbage and it freezes great! Let me know if you want the recipe.