Westeros only has one wall

I was talking in terms of the plot as was quite clearly stated in my post. Don't know if you noticed but Catelyn along with her entire family are all dead, missing or captured at this point. Who was Jaime going to return her to Lysa (a psychopath) ? Or perhaps Roose Bolton (also a psychopath)? The north belongs to the Boltons and the Riverlands to the Freys/Baelish.

It doesn't really matter that much. There aren't any major plot points related to Jaime not being in KL for the PW

They probably start S4 with cat getting dragged out by Nymeria and end the episode with her resurrection which in my opinion would be better than cat immediately being found bearing in mind she was in the river for about 2-3 weeks (probably wrong it's been a while). I think it will have more effect that way anyway as the unsullied will have accepted cats fate by that point and may not even be thinking about her so it will be a shock. This scene was very well done. What people need to remember is that the show cannot simply use inner monologue or conflict to show true emotion. This scene showed that Ygritte and Jon do love each other but that Jon must choose the NW over her in order to protect the realm.