Fill a large glass with crushed ice. Add a few ice cubes to a cocktail shaker. To the cocktail shaker, add the winter citrus juice, lime juice, simple syrup, vodka, and Grand Marnier. Shake for 20-30 seconds, then pour into your glass. Top with the lemon lime soda and stir to combine. Garnish with a slice of blood orange, grapefruit, and/or tangelo!
Combine the blood orange juice, tangelo juice, and grapefruit juice in a bowl. Stir to combine.