3 hours ahead: Combine berries in a large bowl; set aside.
Bring sugar and water to a boil in a small saucepan; stir in lemon juice, orange juice, and Grand Marnier. Remove from heat and cool 5 minutes. Pour warm syrup over berries. Set aside.
Just before serving: Spoon about ⅓ cup Whipped Cream in center of each crepe; roll up and place seam side down on individual serving plates. Top with warmed berries in Grand Marnier Syrup.
3 days ahead: Process all ingredients in a blender or food processor until smooth, stopping to scrape down sides. Cover and chill 1 hour.
Lightly grease the bottom of a 6-inch skillet or crepe pan; place over medium heat until skillet is hot. Pour 3 tablespoons batter into skillet; quickly tilt in all directions until batter covers bottom of skillet. Cook 1 minute or until the crepe can be shaken loose from the skillet. Turn or flip crepe and cook about 30 seconds on the other side. Repeat procedure with remaining batter.
Stack crepes between sheets of wax paper in a heavy-duty plastic bag for up to 3 days in the refrigerator, or up to 4 months in the freezer.
1 hour ahead: Beat heavy cream until foamy; gradually add powdered sugar and vanilla extract, beating until soft peaks form.