For starters, no remotely decent college football program has had to appoint a year-long interim coach because of a vacancy that arose in late December or early January. Year-long interim coaches are appointed when a vacancy occurs in the Spring (Tressel resigning from OSU, Petrio being fired at Arkansas, Kuharich leaving ND, etc.).
Furthermore, only one of the current assistants at ND has any head coaching experience at all. Van Gorder was the Head Coach for one year at Georgia Southern, and he couldn't cut it there. Also, if one or two of the current assistants get jobs elsewhere in the next few weeks (Alford at Colorado State, perhaps), then ND is going to have a tough time getting any remotely decent assistants to come for only one year.