This is my worry. Wasting time on filler (that is to say parts NOT in the book such as Mel taking away Gendry - how the f did she get there in the first place - it's a war zone!) and then mugging up the crucial parts of which there are many.
And John's love story is filler because the book focused more on his inner dialogue and his moral struggle, not some lovey-dovey shit.
It is not filler, Edric Storm is a major part of the Stannis storyline but why create new characters when the audiance is emotionally invested already in Gendry? Both are just Robert's bastards afterall, Melissandre and Thoros communicating really connected the dots for the audiance who havent read the books, they see the lord of light is a major player in the story.
It was a great scene through and through, Melissandre got there by boat up the Trident obviously.
Jon's love story is not filler because his moral struggle was to betray the Night's watch or betray Ygritte and nothing else. It was never about his loyality to the rest of the wildlings or Mance Rayder.