Yes you can use bales around the exterior if you are concerned. You need to wait until we freeze to do so as rodents will move in if you do it earlier.
I use rubber bowls and rubber buckets, and either bash them out, or turn them over in the sun to melt enough for the ice to fall out.
I carry warm water out in a watering can, so sometimes I just top off the ice as well. It's useless to try to keep heated water as ducks foul it up and it needs daily dumping anyways. They do make heated water buckets and bowls if you want to go that route. Ducks will eat some snow too, so if I'm late getting out to the shed they are okay.
Wild ducks winter over in the open rivers around here if they are being fed. They are winter hardy. My muscovy continue to take baths all winter long, so I provide a big shallow tub for them to do so. They often will have icicles hanging off their tails because of it.