Getting premium cabin international awards for more than 1 person, with everyone flying together, can be very challenging. That said, I've managed it several times for my family of 3. The trick is to book well in advance (it often DOES help to start right at 330 days out, as a number of airlines reliably release 1 to 4 seats at that time point on certain flights) and to be flexible with your dates and even your destination.

You've done the right thing by starting to look for availability patterns >330 days out. Now try looking at alternative flights and destinations. Look for the number of seats released this far out between gateway cities in North America and Asia (or wherever your destination is) by every *A carrier. If you find a route that generally has good availability (i.e., 2 or 3 seats on almost every flight), try to build a routing around that.