I haven't had trouble with this in years. But you have to be ready in case it happens.

Other options are 1) if you have any type of airline status (or know someone who does and would help you) that allows cancellations of award tickets for free, just book one and then cancel after arrival.

Also 2) you can book your own fully refundable airfare, and cancel later, but it's usually more expensive up front. And be careful about floating the balance versus having to pay the bill if you buy too early or refund takes awhile, and being comfortable with process to cancel and get refund.