I have PE flights booked (cash) MEL-HKG-NRT and return and want to upgrade with Asia Miles if possible. At least the MEL-HKG segments.

Currently the outbound MEL-HKG is Y4 W0 J9 and only 1 seat available for 2 to select, so looks promising for an Op-Up, we are OWE/OWS, but would rather transfer and spend the miles to secure.

Currently no award seats available, how long pre departure is the best time to call in for an upgrade?