In a medium pitcher, make the sangria mixer by adding the apple slices and lemon juice to the pitcher and stir. Add in the orange juice, orange sections, the cranberry-grape frozen concentrate and the cinnamon. Let the mixture sit for an hour (up to 12 hours) to allow flavors to meld. Just before serving, add the seltzer to the pitcher. Serve in glasses filled with ice.
Optional: replace half the seltzer water with a dry white wine.