I wouldn't "dump" him per se. But, if he was the only thing making me think twice about taking the new job, then I'd take it. If he is really trying to be with me, then when I tell him about my promotion and possible move, he will do one of two things:
1) Drop to his knees and propose to me (to give me somewhat of a valid reason to give up the job and stay with him)
OR
2) Tell me that he will support my decision either way and give me a VALID reason as to why he cannot leave town with me.
If he doesn't do either of these, then I'd leave town on the first thing smoking!!!!!!