Flight cancellation insurance

Colinwr5

I have just booked flights to South Africa for a 6 month stay. I already have medical and personal effects insurance there and will be staying in private property so do not need normal travel insurance. However as my wife and I are elderly and the flight bookings are outward in November and return in April next year I have been trying to find an insurance cover if we need to cancel the trip due to health reasons. Internet searches always seem to just come up with normal travel insurance - anyone know of a company that will meet my needs?