Originally Posted by
JerryFF
Buy the cheapest roundtrip ticket you can get from your preferred airline. If you can't make your return flight, call the airline and cancel the flight. Explain the situation and tell them you will call them back when you know when you can return. It usually costs about $250 to make the change, depending on the airline, but ask what the rules are before you buy the roundtrip ticket.
This would also be my method, but the OP mentioned that BA was one of her preferred carriers for this trip. Be aware that many of the lowest fares on BA are
not changeable at all, even with a fee. Read the T&C's of your ticket very carefully before you purchase it.