Even though Duncan wanted to head out of the forest region initially, once he became a bit sober his reasoning kicked in and he canceled the plan immediately.
While he was indeed yearning to drink more wine, he wasn't stupid enough to go into a turbulent region where the tensions are high, just to drink some wine. He still had some common sense.
If his strength was enough, then it wouldn't matter. He would have gone over in search of some alcohol. But, with his Spirit Sea realm cultivation, he would only be walking to his death if he went over.
So, he ruthlessly suppressed his desire for wine and obediently stayed in the forest region. After his senior brother left, Duncan has been trying to comprehend the soul art a bit more.
