Given the situation where Aubin needs ATLS (Advanced Trauma Life Support) and the closest Level V trauma facility is closed, the most likely outcome is that he will be transferred to a Level III or higher trauma center. This is because it is critical for him to receive the appropriate level of care as soon as possible, and a Level III trauma center can provide the necessary treatment.
Therefore, the best response is: He will be transferred to a Level III or higher trauma center.