Its good to provide a dry area in the run where the hens can go to feed, and just to get out of the rain, especially as they're going to be exbatts not yet used to the great outdoors. Don't put food or water in the coop, it will get messy if you do and the hens wont be able to access it easily either. I just fill my feeder right up to the top and refill when nearly empty but I dont have a problem keeping it dry in their covered run. Its important never to let it get empty, whether or not you fill it right up, as they need to feed little and often during the day, especially in the shorter winter days. But as Chuck says its important that it stays fresh so if it gets damp put less in and replace it more often.