You must have missed the foreshadowing back in season 1 when Hodor said: “Hodor, Hodor Hodor” All makes sense now.
One of the dragons is crowned king then devours the remaining cast except Sam. The final episode ends with his grandson sat on his knee and Sam finishing telling the story. Sam goes to bed and dies in his sleep.
Tyrian has not had a shag since series 2 and fooks the remaining cast into a coma. It then fast forwards 1000 years and Albert Starc, great, great, great, great, great, great grandson of Sansa opens a new drive thru KFC at the new roundabout on the Winterfell bypass.