The dialogue has been problematic ever since they outpaced the source material, IMO.
Unless they're saving Ghost for some epic, just-in-time dramatic entrance, I don't see why he's not at Winterfell. Mind you, looking at what they did to Summer, he'll probably dramatically mid-battle and get skewered within 5 seconds.
It was a decent 'Episode 1' with all of the requisite exposition. However, it seems to me (and I recall thinking this from last season)… for a series that has a helluva lot to wrap up and tie together in such a short time, there continues to be a lot of what I would consider filler.