There is an alternative, of course, which is to swallow the £120 fee (less £40 cashback if you apply via quidco.com), start spending now and when your voucher comes redeem it quickly for somewhere with fewer availability issues.

No reason why, for example, you couldnt get out to Mexico in November this year if you applied now and got through the £10k spend in 4 to 5 months, since MEX is usually OK for availability.

Quite honestly, if you want to go to BKK, SIN or HKG - the real tricky spots for availability - you are better getting BMI miles since availability is cheaper and easier since you can pick from Thai, SQ, ANA, LH, SAS, Swiss etc to get you there.

Alternatively, BA Miles seats to Tokyo and Shanghai are usually available with far less notice. Shanghai to HK is a particularly cheap and easy connection to make.