This is called Stay'n Park or something like that

Usually stay 1 night, park 1 or 2 weeks, but Holiday Inn Express is a big chain, and should not trick you. Maybe they've got a big empty parking lot. I would take the deal if they have 24 hour (at least every half hour, or on call anytime) free shuttle to the airport. You can also ask about parking lot security and distance to the airport.