I'm suprised your finding lots of F redemption to Sydney next February as I booked my flights on exactly 350 days. We've bagged 2 (miles plus 241) LHR>SIN>SYD and SYD>BKK>LHR in F for Feb - but it was only a very helpful agent who kept hold of the outward for us whilst return opened up - and we had to leave all details to him and what he could bag. It worked - but only just.