They don’t need to call more than a 1,000 people. Calling 10,000 or 100,000 would show much the same result. It’s a math thing. One thousand is a common sample amount.
Math is hard.
The article says, “More than 135 million Americans SAY ...”. That is a straight-out falsehood. The true statement is that around 560 people said, and those people, as well as the around 440 who said they had been on vacation, were not a statistical microcosm of the United States. They were simply 1,000 people who answered their phones and didn’t hang up when they realized it was a poll.