To make ahead:
Place all items in freezer bag. Toss and freeze.
When ready to cook place all ingredients in crockpot and cook for 5-6 hours on low or 3-4 hours on high. Remove chicken from mix, shred and then add back into the mix. Serve with warm tortillas and top with salsa, guacamole, shredded lettuce, sour cream and shredded cheese.