slice it up. vaccum seal the slices. freeze or refridgerate. when preparing get a big pot of water boiling and throw the bags in the water until they are hot. should be just as if they came off the smoker.
I slice & seal and seal whole, both come out fine. Don't know if you have a kohls near you but they usually have good sealers cheap and you can usually find a 20% off coupon.
I like slides and sealed, then you can reheat it in the bag really quick. If you reheat the whoel brisket, it takes a while and can cause more dryness IMHO.