If Hank and Firo were to go at this for approximately 4 hours, they'll eventually be able to break the smaller door located near the mess hall entrance down and enter. They'll likely be somewhat sore for awhile if they don't recruit someone else onto their door busting team, but it's still feasible with only the two of them.

Once they enter the room, they'll find something akin to a pantry that withholds a stash of food and first-aid related amenities. It seems to be enough for approximately 100 people.