In that case, why the hell would Stannis sail North and march into battle with only 1000 men? I mean...the battles in the South were between armies nearing 100,000 men...and Melissandre said they meant nothing compared to the real threat in the North.Hi army isn't actually very big. In the book, I think it states he has about 1000 men on horse who just happen to be well-trained and organized -- easily routing the much larger but highly disorganized tribes of wildlings that also consist of many non-fighters. As Mance mentioned, they just want passage to settle down in peace and safety somewhere south of the Wall before winter arrives. They're not equipped nor trained nor intent on invading and conquering.
Am I missing something? Did Stannis just get lucky, or did he have more information?