In a medium bowl, stir together the wine, water, and Cointreau. Add about 1/4 of the strawberries and the orange slices. Marinate for 2 hours in the refrigerator.
Place the remaining strawberries in a separate bowl. Sprinkle the confectioners' sugar over them. Cover and refrigerate as well.
To serve, mix both bowls of berries and sauce together. Scoop ice cream into serving bowls, and spoon berries over the ice cream. Drizzle with some of the marinade.
