Elaine1, agreed re business class. I was just grasping at straws. Regarding flights. It depends, some are non-refundable, some are refundable except for a relatively small admin fee. Fortunately, my flights to Johannesburg were booked with avios (airmiles) and are refundable (with a £70 each admin fee) up to 24 hours before departure.
I emailed the safari lodge this evening, explaining the situation (they apparently have no cases in South Africa), including age, pre-existing health issues etc. I said that I didn’t want a refund, just to push back the dates, asking if, in the circumstances, they would allow a deferment until the virus flattened out, without charging me a penalty. They might go for it, since all of the travel industry are suffering from cancellations and lack of bookings in the situation. I’ll lose money on the internal flights and other bits, but better to push it all back 5/6 months - max I’m guessing. The more I think about it, the more I (and my usually carefree husband) think negotiating airports and flights is a bad idea at this time.