Don't think anything will go wrong, the worst that might happen is that the last 1/3 of the season becomes a closer shave than the first 2/3, and that would only happen if the club lost a key man like Howard. The team have lost one key man through Tunchev already another - especially Howard - would put the team under some strain but not enough to derail the team I don't think. (Besides, there's always the loan system to come to the club's rescue if it needs to replace someone key or senior such as Howard, Oakley etc... I think MM's would back NP for that). So a close shave maybe, but not failure to achieve automatic promotion.
Another danger someone might mention is complacency. But I don't seee this happening under this management. NP is far too disciplined and goal-orientated (no pun intended) to allow undue complacency to set in. From April if the club are still over 10 points clear of 3rd place invevitably this might take the edge off some performances but NP would not allow it to go beyond the odd allowable game or two.
I think the more interesting question, for another thread, is how to take a great season forward to the higher division.