Heat oven to 250°F.
In ungreased large roasting pan, melt butter in oven. Stir in tequila, seasoned salt, red pepper and dry margarita mix. Stir in cereals, nuts and pretzels until evenly coated.
Bake 1 hour, stirring every 15 minutes. Stir in cranberries. Spread on paper towels to cool, about 15 minutes. Store in airtight container.