As an aside; Vito died before they could move to Nevada. I would guess that Vito would not have left New York. For that matter would Michael have left? Michael makes a comment in GF that he wants Carlo to be his right hand man when they make the move to Nevada. We can assume now that the comment was made strictly to put Carlo at ease while Michael confirms his suspicions about Carlo. But that statement could imply that Michael was moving to Nevada and not staying in NY, but it could have just meanet that "we" was the business and not necessarily Michael in the flesh. Then Pop dies and plans change.