Another idea would be to put them on old cruise ships that have been mothballed. A typical ship can hold 3000 guests and that does not include the crew. Many of the deluxe rooms will have to be modified to reduce their size. I can imagine the banquet room having all the luxury as when they served passengers. It would be there they would get encouragement to get treatment for their drug addiction.
We could probably anchor them somewhere closer to the poppy fields too. Cut out all the transit time and money.