I have $1,000 in Delta Vouchers that expire in November, but I just can't find a good way to use them because I usually fly from O'Hare to London (or fly within Europe) and taking Delta from there always involves a time consuming connection, while American has a direct flight. Is there a way I can delay the expiration date of these vouchers? Alternatively, is there a way to use these vouchers for flights out of London to other cities in Europe? Thanks for any help.