It depends what you want to do with it afterwards. It won't be much cop for stir fry etc as it will go soggy but to just cook, or use in gratins, bubble&squeak etc it will be ok, I have frozen red cabbage before then cooked it into Flemish cabbage and it's fine.
What about making sauerkraut if you have that much? It's a little complicated but the trickiest bit seems to be finding the most appropriate container to make it in.