If Northerly was mine I'd set it for the Caulfield/Melbourne Cup and give the Cox Plate a miss. Reasons;
1. No Sunline to contend with
2. At 56kg this is about 2.5 - 3kg under wfa - not badly treated for a 5yo of the highest quality.
3. There will be another Cox Plate next year. If he keeps winning he'll get 59 or so in next years' cups and that makes it hard.
4. I get the feeling the way he hit the line at the end of the Aus Cup that 2400+ might be his go now that he is a year older.