HBO - Game of Thrones SPOILERS INSIDE. you have been warned

[Jakensama]

With Sansa and Jon it is not clear whether they can or not even if their are hints.

Jon can Warg.

http://awoiaf.westeros.org/index.php/A_C...Chapter_53

I wouldn't be surprised if he could but that was a wolf dream not actual Warging. I don't recall anytime he was running around in Ghost body like Bran, Arya or the Wildlings do.

I think it's just a level of how developed you are. Bran's the only one with any modicrum of control over it, and thats because he is a gimp. Arya's warging was dream level too.

Also, the wildling warg guy noted that Jon was also a skinchanger.