I think the smaller containers would hold up to freeze/thawing cycles much better than larger gallon size ones. I regulary freeze the factory sealed arrowhead .5 liter bottles completely solid without problems, I think there's enough air space and a small enough amount of water that expansion isn't a problem.

Also, if you have to room to keep your water and food in a small ice chest or cooler, it will help. The cooler will insulate from temperature changes, and the mass of water will keep the temperature pretty stable. I sometimes use it to help keep things cooler in heat, but I suppose it would work the same for cold.