How exactly does that experiment prove anything. The experiment isn't about whether a person could survive on it. It's whether or not that Jeff could survive on it. His costs for housing, food, transport, etc are already based upon his current income.

If he had to suddenly live off a lower amount of course he couldn't.

Could the average person who works for minimum wage survive on it is the question. And yes, they could because literally hundreds of thousands of people do.