He'll die. In season eight's "A Knight of the Seven Kingdoms," we see Jorah approach Dany and passionately tell her how much he's enjoyed their ever-evolving relationship, and that she needs to full trust Tyrion as her Hand of the Queen. In other words, he's basically saying goodbye to his Khaleesi without actually saying goodbye. So, we're calling it now: Jorah is going to die valiantly, doing his father's memory justice as he takes out wights with his new Valyrian steel sword.