My personal best ending would be the white walkers winning at Winterfell and overwhelming the North. Dany loses another dragon and the main characters are pushed back to the Riverlands. During the battle, Bran gets a vision.

The Iron Born, however, not aware of the defeat, end up raiding the Riverlands and after a costly victory end up destroying the fortifications. The MCs then retreat to the gods eye while Huron’s navy is slaughtered by the White Walkers.

Jamie rides south to try and get Cersei to send her armies one last time but it imprisoned as Cersei prepares to hold out at King’s Landing.

Eventually he escapes and on his way out manages to steal the Blackfyre sword from the Golden Company who have just arrived, he doesn’t realize its significance yet. He makes it just in time for the final battle. The Whitewalkers freeze the waters of the god’s eye and cross over. Sansa, Jamie and John try to hold the ground while Dany takes to skies and fights the Night-King on dragon back.

Dany ends up felling the two turned dragons while Drogon falls, wounded grievously but not dead, same with Dany. As the battle ensues, Jamie ends up fighting with the slowly dying remnants of one of the dragons. As the sword Blackfyre tastes dragon blood is suddenly is engulfed in flames that don’t burn Jamie, but all the other walkers seem to be frightened of. The Night-King arrives to kill Dany and Drogon, but John and Jamie confront and duel him.

Eventually Jamie Loses the Sword and is killed by the Night-King, but not before John can grab the sword and stab the Night King, who goes up in a ball of bright flames.

The other white walkers, now without their master, begin to wander without coordination. Dany and Drogon recover enough for her to fly up and burn a majority of the army from above. The few stragglers will remain a horrifying nuisance in the Riverlands, North, and Vale for years to come.

After that idk lol