Can anyone please enlighten me on how to best freeze cabbage rolls?

The recipe I usually use is for the crock pot (from Saving Dinner). Normally, I would parboil the cabbage, stuff if with a meat/rice mixture (uncooked), top it with a tomato sauce mixture and the rest of the shredded cabbage, and cook.

So at what step do I freeze? I planned to follow the same steps, but freeze just before cooking. Will that work? Here are my questions specifically-

Do I still parboil the cabbage before freezing?
Do I freeze the rolls with the sauce, or put the sauce in a separate bag to freeze, and pour over the cabbage rolls before cooking?
Can I freeze uncooked, and then put the rolls into the crockpot (either frozen or thawed) to cook?
Or do I need to cook first, then freeze?
If I cook first, how do I cook in the oven instead of in the crock pot?

Sorry for so many questions, but I really appreciate your help!