My brother threw a speculation at me this morning which I've been unable to find anywhere online and I think it's got merit. We both firmly believe Jon will be resurrected and that he is more than likely Azor Ahai/Prince that was Promised. The speculation is how Jon gets resurrected. In all likelihood the NightsWatch will burn his body given what they know about the dead coming back as wights. There will be much in-fighting amongst the Watch/Wildlings. Davos is at the Wall and will learn about Melissandre burning Shireen alive. No one is protecting Melissandre anymore (other than her own magical powers, which she seems uncertain of after realizing she read the signs wrong and she erroneously backed Stannis). What if... when the Watch go to burn Jon's corpse, Davos ties Melissandre to the funeral pyre (like Dany did to the witch that caused Drogo's state and Dany to lose her baby). Give a life to bring back a life (or whatever the saying goes). So, in a sense Melissandre does resurrect Jon, but at her own sacrifice. And, further, if they put Longclaw with Jon when they go to burn him, Jon would then extract his own sword from the fire --- Lightbringer.