I'm slightly confused why so many people don't think 'Et tu, Brute' is going off. Hardhome was a great action sequence, and Jon got through it alive. Now surely, for Unsullied, they will believe all is good for Jon now- until at least another large scale sequence with the WW. All I can see is they will do it for the final episode, after successfully lulling people into a false sense of security now Jon has survived an immediate threat. Classic storytelling technique.
I quite liked this episode (not as much as a lot of people) but I also considered the whole 'water' issue. I thought it connected in future maybe to; Melisandre's speech of the 'Stars will freeze. The cold breath of winter will freeze the seas and the dead shall rise.' when burning the seven during S2Ep1(?) Also, the allusion to the four horsemen of the apocalypse was pretty cool when the WW were atop the mountain.