Just some thoughts from a camper point of view that I hope to use in my own bus...
Use a coleman stove to cook at first. When hurricane Isabel blew through our area in '03, our block was without power for 2 weeks (and it was HOT). We had a two burner coleman stove that ran off a small propane cylinder (not a tank, just a cylinder) and cooked for MONTHS on a single cylinder!
Yes, we liked cooking with gas so much that we continued to use the little propane-powered camp stove LONG after we had power again. These little stoves and fuel are cheap. And now that camping season is here, you won't have trouble finding a source of propane cylinders. You can get a Greatland 2 Burner Propane Stove from Target for under $50.
Small refrigerators are expensive! Even the dorm style can cost up to a couple hundred. Do yourself a favor and invest in an "extreme cooler". Again, Target has a Coleman Ultimate Extreme 50-qt. Cooler for $80 that has wheels so you can easily roll it up to the ice machine. Keep your ice in a large tupperware container (like a cake topper or bread saver) or some other water-tight container to minimize leakage into your food. In a pinch, those gallon ziplock bags work well enough (though there is some leakage after a couple of uses).
Food in general:
When you can't get fresh food at the grocery store, take advantage of canned foods. They are relatively inexpensive, keep for long periods of time without spoiling, and you can keep both meats (tuna, chicken, ham, and beef) and vegetables. Buy a club membership at SAM's, COSCO, BJ's, etc. Those bulk buy places really WILL save you money when shopping for food. And you only have to shop once a month or so. My husband and I did the math, and we saved about 40% off our normal food bill! WOW! Of course, the variety is aweful, but the tradeoff makes it worth while.
As someone else said, look into a composting toilet. Make one if you can for a LOT less money. As long as you maintain the composting process, you should be okay.
Those 7 gallon jugs of water are HEAVY. Get yourself a collapsable cart that many of the elderly use to carry their groceries home.
As for drinking and cooking water... If you trust the water coming out of the hose, then use it. Otherwise, boil everything you use for consumption first, then store it in a recycled 2 or 3 liter bottle for use later. Personally, I hope to use those huge jugs that Walmarts/Lowes/Homedepot often carry outside that are recycled constantly. Just turn the empty jug in for a new jug, or refil it at the vending machine.
This is just the basics, but should help at first. Look to the camping world for quick solutions and add more substantial items as you have time and money.
With a little ingenuity, you can stretch the dollar quite far!