For as much love Syrio gets on here, this sub seems to neglect some of his most important words to Arya. We all look but we don't see. Season 5 is not going to spoil anything significant from TWOW, and here's why I think so:
- Lady Stoneheart did not appear in Season 4, but is a fairly big part of Jaime + Brienne's story nonetheless.
- All signs point to Jaime in Dorne next season, which means his Riverlands story has been delayed.
- Sansa's story next season has been confirmed to be changed from TWOW (show-only plotline like Craster's in S4). An expected "tour of the Vale" for S5.
- Brienne will travel around the Riverlands + Vale for most of S5 following her AFFC story. By the end she will confirm Sansa is okay as well as Arya (who she just met) which is the information she will use to spare her life from LSH at the end of the season (rather than "sword".)
- Jaime will be in Dorne to introduce the Sand Snakes, Doran, etc. If the speculation about Trystane assuming the roles of Arianne and then Quentyn, we could assume Jaime returns following Trystane's departure. This allows for the ADWD/TWOW material with Jaime, Brienne, and LSH to appear in S6.
- People worry about Bran's story spoiling stuff for TWOW but let's face it, there's only two paths his story can go in S5: Greenseer training and historical flashbacks, or Greenseer training and more information about the Others. Since we know the Others don't do anything by the time Jon is assassinated, anything we get this season on them would be background info, like S4E4.
- As a side note, we will get Balon's death this season, timed with Asha's arrival at Pyke. Someone will tell her that her uncles are returning home, all with claims to the Seastone Chair. This sets up Kingsmoot for S6 and explains the lack of castings for our beloved Greyjoys.
TLDR - Don't panic.
Edit: Don't forget that Jon, Tyrion, Dany, Sam, Cersei, Arya, and Reek will all have their ADWD stories, which is where most of the meat for the season will come from.