The only place I have seen it for sale in recent months was direct from the Portal Games website, but right now it is marked as unavailable. In their shop you have to look at the "mini expansion" drop-down. They have 8 items currently available and another 7 currently unavailable for Robinson Crusoe.
Your best bet is to print the official PnP version that is available in the files section for this BGG item. You can find all sorts of scenario PnP files in the main Robinson Crusoe entry.