Difficult one. A relegation battle, especially if he plays a part in either Villa or Norwich staying up, could be the making of him. On the other hand, they could be too terrified to give him the minutes when it really comes down to it, or if he's not immediately performing.
Also, I forgot about Kodja at Villa. He's rubbish, but he is their back-up to Wesley, and would be an obstacle for Nketiah to get past if he went there.