This tea can be made up to five days ahead and stored in an airtight container in the refrigerator.
Combine tea and mint in a large heatproof container. Pour 8 cups boiling water over; let steep 5 minutes. Discard tea bags and mint; stir in sugar. Let cool completely, then stir in orange and lemon juices. Refrigerate until chilled, at least 2 hours.
Fill glasses with ice. Stir tea and pour into glasses. If desired, stir a shot of whiskey or gin into each. Garnish with citrus rounds and mint sprigs; serve immediately.