60 minutes transfer from Domestic to International at MEL, can I make it?
 

As titled. So Virgin Australia decided to launch HKG with A332 aircraft from MEL. As a SYD passenger, I have no choice but change at Melbourne for that flight. (It turned out to be a pretty good deal, for $99 + 34800 points I can fly overnight from Sydney to Hong Kong, which is much cheaper than CX138).

On the day of flying, I have can choose between 8pm departure from Sydney or 10pm departure. If I choose 10pm departure, it will arrive MEL at 11:35pm and my flight to HKG will depart at 12:35am the next day, leaving only 60 minutes for transfer.

May I ask is there sufficient time to transfer between the 2 services? Consider I will need to clear immigration and do the security check again? What will happen if my 10pm Melbourne service is delayed? Can I ask for MEL to hold the plane for me?

Finally, for such flights, what time should I be arriving the domestic terminal for check in? Is it still 45 minutes before the scheduled departure, or need to be earlier?

I would take the earlier flight.

While DOM->INT transfers at MEL are pretty straightforward with T3 & T2 being part of the same building, I would not risk an hour connection.

you still need to navigate emigration and your HKG flight will begin boarding 15 at ~11:50pm.

(They may or may not hold the flight should you be late into MEL.)

MEL is quite easy to transfer in. This should be possible however it is very tight. Flight delays are more likely at the end of the day as any disturbance mid-day can have after-effects. So in my opinion it is too risky. I'd take the 8pm.