Had already paid the deposit on a holiday to South Africa for June and balance was due at the end of March. Figured it was unlikely to go ahead - even best case scenario it would have to be massively changed - so just before payment date, rang up the travel agent and asked them about moving the dates to October instead. They did it no problem, basically keeping the exact same itinerary, just pushing it back four and a bit months. Cost was almost identical (gained on one thing, lost on another but pretty much cancelled themselves out), plus now full balance isn't due until August, so it gives us more time to save up. And if things aren't back to normal by then, we'll look to see if we can move it again.