I get your point - I know that the sons’ wishes are competing with the wishes of the father and that a dying man is entitled to have his wishes honoured. A dutiful son will honour his father’s wishes over his own, BUT I feel sorry for the sons if they are denied the opportunity to make the most of these last months with their father, especially since the move may hasten his death.
At the end of the day, whatever Allah wills will happen and may Allah grant the family the courage and grace to go through these tough times.