I think Jon’s making the right move. History isn’t on his side but damnit, it’s what needs to be done. He made a smart move in giving Sansa control of the North. Sansa’s dilemma will be 1) give in to whatever Little Finger eventually proposes, or 2) stick with her wolf-pack. I think she’ll eventually decide to side with the Stark pack and Jon Snow.
It’s a targeted move going to the south, as Jon trusts Tyrion along with Sansa. Seeing 3 Targaryens (unconfirmed) together in Dany, Jon, and Tyrion could lead to the 3 dragons recognizing them as blood (although, Jon and Tyrion aren’t blood of the dragon).
If I can quote the nWo red and black, “don’t turn your back on the wolf pack, you might wind up in a body bag.” (Wrestling fans, anyone?)