Given Shang Yu's current physical condition, he definitely would not have been able to hold out for this long using the Water Courtesan's ability.
The ginseng slice Qi Jingtao had given him was of a fairly old age, which was enough to keep him hanging on.
Actually, Qi Jingtao could have easily taken action himself to find the whereabouts of Xiao Nan and the others. Seeing the situation now, Shang Yu understood that Qi Jingtao purposely wanted to give him a chance to gain some experience.
Chapter 49