As for whether Westeros (or Bronn, who very much wants the dragon as far away from everyone as possible) will see another dragon, it’s unclear. We have a feeling if Drogon wanted to stay in Westeros and avenge his mom, he would have already. But given that he melted down the Iron Throne, aka the true villain all along, we think he’s probably living his best life far, far away. We wish you all the best, Drogon.
Source : https://www.distractify.com/p/drogon-game-of-thrones-season-8-finale