Some have guessed that the true story arc is between the Whitewalkers and the Red God and having to deal with the reawakening of magic by Daenerys and her hatching those Dragons.
Not to mention if Melisandre manages to save Jon with her Red God magic. I mean after Thoros resurrected Catelyn it's not that unsurprising that Melisandre would resurrect him since she keeps seeing "Snow" in the fires.
Personally, my theory is that the south is showing how the Westerosi mess up before the long winter comes. Because, as is being shown with it being Autumn and all, and pardon me using the saying but it's appropriate as all get out, winter is coming. And most likely the Whitewalkers with it.