Is it permissible to remain abroad and circumvent the terms of the scholarship in order to avoid paying the resulting costs, by taking advantage of the condition of accompanying one's wife?

The condition that this person committed to in order to receive the scholarship must be fulfilled, as Allah Almighty says: "O you who have believed, fulfill [all] contracts." Therefore, he must return to work in the requested town or return what he took for the scholarship costs. It is not permissible to resort to deception to avoid what became binding upon him.