Yes, you can certainly freeze the leftovers from this recipe. To do this, let the roast cool to room temperature and wrap it tightly in foil or plastic. Then, place the wrapped roast in a resealable plastic bag and freeze it for up to 3 months. When ready to eat the leftovers, thaw the roast in the refrigerator and reheat it in the oven or pellet grill. Be sure to use a meat thermometer to ensure that the roast is heated to the desired internal temperature before serving.