I still think an ending where the night king is like "you humans can't stop bickering, so now I am here to turn your sorrow against your" and just destroys Winterfell, marches south as a handful of survivors try to outrun them and warn everyone. The night king goes around to every major battlefield from the series and raises all the bodies. But Cerci is boastful and tries to fight the white walkers, but they destroy King's Landing, and the last scene is just like 10-15 people who survived (like 10 main cast and a couple of randos) on a boat on their way to Essos because Westeros was completely overrun.

Not only would it have been a real ending, but it would have had a cool message that the infighting which is the "game of thrones" is not only pointless but actually detrimental, and ended up destroying the nation.