-By the end of ep 1, the following characters will have reached Winterfell (cue mass complaints about travel time): Jon, Dany, Davos, Gendry, Jorah, Tyrion, Brienne, Pod, Missandei, Grey Worm, Varys, The Hound, The Unsullied, The Dothraki, Drogon and Rhaegal. Plenty of reunion scene potential here, Arya x Gendry, Arya x Hound, Sansa x Hound, Sansa x Tyrion, Jon x Arya, Bran, Sam, and Ghost (lol).
-Lots of characters are probably going to meet for the first time at Winterfell. Possible meetings of note: Jorah x Lyanna, Dany x The Starks, Dany x Sam (she killed his Pa and Bro), Sansa x Varys (they both lived in KL but I'm not sure they've ever spoken, he might inquire about LF) Also, seeing Dragons at Winterfell is gonna be surreal.