As for how they pulled off creating such an intricate weaving of images, they owe much of it to technology. Once they finalized the design, which features Eleven, the Mind Flayer, and silhouettes of the boys on bikes, they employed the help of special GPS equipment to plant the field with seeds. Then, they let it grow, and -- ta-dah -- it's filling in quite nicely, as you can tell from the recent aerial photos shown above.
It's tough to say how long it should take you to get through the whole thing, since it all depends on your navigation skills. But, unless you're really bad at navigating, you should be able to complete your journey before the show's next season drops. You also have some time to brush up on maze strategy, since the site doesn't open for the season until September 14, the same day another hotly anticipated Stranger Things attraction is scheduled to launch at Universal Studios Hollywood and Orlando.
In any case, if you're interested in making the trek to Lafayette, you can score tickets to the maze here.