In its first season, Game of Thrones made it extremely clear to us that no one is safe in this world. In fact, it's a good bet that the more beloved and morally sound a character, the more likely it is that they will be dead by the next season. But what about some not-so-lovable characters? Will Littlefinger die in Game of Thrones Season 7? He's one of the cannier characters, so that could just be wishful thinking on my part.
So far, we've lost many of the noble, loyal, brave-hearted Starks, which leads the observant viewer to conclude that in order to make it in this world, you've got to be more cunning, more secretive, and more ruthless than Starks tend to be. If the Starks are the Gryffindors of this world, the Slytherins tend to be the ones who make it out alive. And if we were to assign Littlefinger a Hogwarts House, he would most definitely be a Slytherin. So far, Littlefinger has always been one step ahead of everyone else, making the right alliances, and betraying them at just the right moment, so that he always comes out ahead. Sansa told Jon, "Only a fool would trust Littlefinger." So perhaps he has finally slipped up, and his game has gotten ahead of him.
Personally, I would kind of love it if Littlefinger was no more. And it could definitely happen. Plenty of people are predicting that Littlefinger is going to try to build a wedge between Jon Snow and Sansa Stark. This is almost guaranteed to happen. In the Season 7 trailer, Littlefinger is shown saying to Sansa, "Your father and brothers are gone, and yet here you stand," hinting that she's more fit to rule in the North than Jon Snow. (She might be.)
Littlefinger will probably try to use his army of soldiers from the Vale to bargain his way into a position of power in this little court in the North, and try to weasel his way back into Sansa's heart and turn the long-lost siblings against one another. I just don't think that after all that character growth, Sansa will be willing to put up with his shenanigans anymore.
In fact, neither Stark sister appears to be in a mood to take any prisoners right now, and it looks like Arya Stark is going to be back in Westeros this season. Let's not forget that Littlefinger was instrumental in Ned Stark's beheading (even if she doesn't realize it... for now), and Arya is not exactly a forgiving type of person. It has been speculated that Arya will come back and kill Littlefinger, which would (hopefully) indicate that she's also going to reunite with her siblings in Winterfell.
Could it be possible? This is Westeros, so anything is possible. All I know is that it's going to be bloody.