Omega Vision
Face Flowed Into Her Eyes
They realize that they've taken too much time to move the chains, and since they decided for some stupid reason to shorten their run (I don't think viewers or HBO would have had a problem with the series lasting 8 or 9 seasons, but they've essentially shortened it to 7 just because) they realize they now have less than 20 episodes to wrap up a bunch of plotlines that have taken 50+ episodes to set in motion.
I imagine the final scenes of the season will show Dany and her army setting sail on the Iron fleet (which will have been constructed in a matter of days because of the stupid timeline that kept the Ironborn stagnant until they were suddenly plot relevant again) while the White Walkers arrive at the wall, perhaps breach it.
On a sidenote, does anyone else feel like Arya's plot line was a waste of time?