Quest \"to Collect all the cards for guinta\" [is the answer] (The Witcher 3: Wild Hunt)

Anyone could do this quest? I just think that it is almost impossible to perform. After all, some merchants may disappear in the course of the story, (as for example in the village of Stagery), and all, the quest is not complete. Kind of went around to each merchant, bought and won, but the quest is not completed, so I think that blew some dealer and now does not fulfill the quest. Is it possible to get all the cards without traders?