Whats the best stratergy for booking over christmas? I have 2 upgrade vouchers, one on my account and one on my wifes. The plan is next Christmas to go to South Africa, Avios seats dont open until 365 days however if I wait until my return date passes and book as a single return ticket my outbound flights are likely to be taken up. If I book single outbound and use the upgrade voucher on the out, on the return its not possible to use since i understand its only possible to use the upgrade voucher on departing the UK.

What is the best way to get this done?