Nope. Condensation occurs when the cold camera surfaces come in contact with warm, moister air. So if you trap the camera in a bag with outside
air and let it acclimate without opening it, there isn't any condensation. The cold air has too little moisture in it to condense and the warm, moist air can't get into the bag
That's why I double bag, though--in case there's a pinhole leak in one bag that might allow moist air in before the camera is warm enough.