I’m starting to think about a trip to New Zealand in late 2024 or early 2025 and would love to use my Amex premium voucher(s) for reward flights, I’m also a solo traveler so will be using them for the 50% avios discount.

I think my only option to use the voucher(s) is LHR->SYD->LHR and then a cash flight on to New Zealand.

I would prefer to take the trip early 2025, but I have an Amex voucher expiring in oct 2024 and another in 2025. Would it be easier to get availability using these vouchers on the day the flights are released, rather than a return using one voucher.