Eric Stevens of Rochester, NY recreated his LEGO replica with the help of ground and aerial photos of the castle (and a digital designer) as a Christmas gift to his girlfriend, fellow Downton fan. Perhaps LEGO will take the hint and make a Downton LEGO set?? (Read more about it here.)
Perhaps even more impressive is Curtis Jensen's 2012 time-lapse video of him painstakingly recreating the Jacobean structure out of gingerbread. Amazing.
P.S. For more info about the real Downton Abbey, visit Jane Austen's World. Not only will you see detailed interior shots, but an actual floor plan too.