Yang and Prompto will be able to force their way into a room together, yes! And what they will find will be a storage room of some kind (how many space closets does this place have??) that contains mostly empty boxes. Searching through all of them, though, they will find a crate of water bottles. Though about 1/3rd of these bottles are empty, there are still approximately 25 full bottles of water that approximately equate to 16 ounces each.