Preheat oven to 375°. Line a baking sheet with a large piece of heavy-duty foil (about 18x12 in.). Place peach halves, cut sides up, on foil; drizzle with honey. Fold foil over peaches and seal. , Bake for 25-30 minutes or until tender. Cool completely; remove and discard peels. In a food processor, process peaches until smooth., Transfer peach puree to a pitcher. Add the nectar and 1 bottle of champagne; stir until combined. Pour into 12 champagne flutes or wine glasses; top with remaining champagne. Serve immediately.