I like to pretend I'm driving a boat and enjoy the sightseeing and people watching. If he finds something he likes, he has to find me with the cart eventually!
>While the U.S. Border Patrol primarily operates within 100 miles of the border, it is legally allowed “to operate anywhere in the United States,” the agency added.
Just don't book a round trip, don't check a bag, don't do it too often. Also you're gambling that they don't cancel your flight and book you on a new one to the city you don't actually want to go to (that no longer connects via the hidden city). You can get half price tickets sometimes with this trick.
Your solution seemed very smart, and I have no doubt that you are an excellent programmer. However, I think you way over-complicated things by choosing to go the functional route. Here is my go in imperative Python. The base-15 trick is still needed, but the rest of it seems a lot easier to understand for someone reading the code later.