For potable water, I do recommend a water service. A couple of years ago we bought a water cooler and now have the big jugs delivered and picked up at a very reasonable cost. Doesn't solve the bathing problem, but at least we always have a good supply of drinkable water for ourselves and our pets, should the city supply be compromised.
For the generator, could you just get a small one that can power a fan in one room? Might be a lot more efficient than trying to cool the whole house - I though AC systems were particularly high energy users.