No matter how large your rig is or how much storage space you think you have to fill, the weight of what you store can be a problem. Cans and bottles are heavy. Boxes of cereal are bulky and contain air ("This package is sold by weight, not volume. Contents may have settled during shipment"). If you remove the cereal and put it in a gallon-sized plastic zipping freezer bag, you have removed the air and can stack the cereal anywhere.
By shopping at brick-and-mortar or online stores that offer bulk food, I can purchase soup mixes, textured vegetable protein, dehydrated vegetables and fruit, cereals, granola, flour, sugar, grains, spices, etc. I order soy-based meat products online from a company in Tennessee (I'm vegetarian). I've served soups and stews made from ground or chunk "chicken" and "beef" to my fellow RVers without anyone realizing the dishes contained no animal-based products. A company in California provides organic dehydrated veggies and fruit; you can order online. Another company in Idaho has ready-to-eat organic food in single serving pouches. You add boiling water, fold the top over, wait, stir and eat. Since the pouches have no aluminum foil lining, they can be burned in your campfire. The food is light enough to please backpackers, requires little preparation and is delicious. There are no dishes to wash and no waste.
If you boondock occasionally, and most of us do, bulk food only requires hot water to reconstitute and limited fuel to prepare. A dehydrator is a great way to dry fresh fruit and vegetables in season if you're near a farmers market and store them in inexpensive square or rectangular plastic containers.
By doing a little renovation inside my 18-foot motorhome, I've created quite a bit of storage. Based on an idea from Bill and Jan Moeller in The Complete Guide to Full-Time RVing, my couch was removed and replaced by a six-foot counter top over two kitchen cabinets with four drawers each. This created storage, a desk and a great food preparation area. All my bulk food is stored on cabinet shelves or in drawers. The food includes that large box of cereal, cookies and pasta. I've never had a problem with critters. My rig has a two-month supply of food that weighs less than 25 pounds.