ironshaolin
First question is how long you will be staying "There' after the problem starts. If, like me,this is what I have to work with. start by deciding how much you et now.
Then look for unused storage in unusual places. if you live on the top floor there is probably an attic or roof access in one of the closets. If you live in the middle there is just what you have.
SOme ideas are how many days a week can you eat the same thing? That leaves Rammen noodles. If mixed with water makes noodles and soup. If mixed with eggs makes gooey, but good, pasta type.
If you have MRE get rid of the air filled balloon sack. Don't throw it a way just get the goods out and put them in a shoebox. Makes shopping easier.
If your kitchen cabnets have a dust cover over the top pull it down (CAREFULLY OR THE RENTAL COMPANY WILL EAT YOUR LUNCH) and make it where it lifts up and store up there. The laundry area has a lot of wasted spaces.
See what I mean. The space to store food is everywhere. Even under the bed.