One could potentially find an uninhabited island with soil and water among the islands in the world, like 1 out of the 5000 uninhabited ones in the Philippine archipelago. One could even hide out in a remote location on land in a random large country, like Russia.
It might take some work, but it seems possible to me.
Such a trip costs money. To secure the legal right to inhabit the island, to make the trip, and to bring enough supplies to survive.
A person either needs to use his parent's cash or to work for a number of years and save before leaving. The "choice" isn't available to him until that happens, so either his parents must work to purchase their child's freedom, or he must work to purchase it himself. In either case this is one of the very definitions of slavery.
It might take some work, but it seems possible to me.