Bring sugar and water to a boil in a medium saucepan, stir until sugar is dissolved. Remove from heat; pour off all but one cup of syrup, reserving any extra for another use.

Heat the syrup to a boil and then reduce heat to medium. Add the cranberries and simmer for 2-3 minutes until they just begin to burst. Remove from heat and let cool in syrup.

Place 2 Tbsp drained cranberries and 6 Tbsp cranberry syrup in a large pitcher; add the lemon wedges and orange slices. Using a muddler or wooden spoon, vigorously mash the fruit.

Stir in gin and let steep for at least 5 minutes. Strain into a medium pitcher.

Fill 4 glasses with crushed ice and 1/4 cup ginger ale.

Fill a cocktail shaker with ice and then pour half the cranberry mixture into the shaker and shake vigorously for 10 seconds, strain liquid into two glasses. Repeat.