Whatever works for you is what matters. We have a generator that will pump water and run the rest of our household essentials for quite a long time if used sparingly.
Our well water is bad, even the dogs will not drink it, and thus we rely on the artesian spring. We can also get water from our lake to flush the toilet if all our back-up options fail.
People in the areas that expect to lose electrical power might want to check to see if there are any safe artesian wells in there area. They are not always well publicized. Those who sell water do not usually like a free water source widely known to the public.
We had a generator that pulled the well pump, used it for maybe a couple of years until we got electricity. But we sold it recently because we’d rather have a non-gasoline method for long term disruptions. But IMO large tanks is the way to go if one has no other method, such as a shallow well, artesian spring, lake nearby etc. Some windy areas can use windmills to draw water up.