After a few requests and vote in the council, due date has been extended to 12/23/19 at 11:59 PM EST. Thanks for your understanding!
In addition, since the extension is on such short notice , FAMs that submit entries early before December 10th 2019 at 11:59 PM EST will be getting a gratitude bonus (that does not associate or deter them from winning prizes) for being on time for the first deadline.
Final resolution size answer : There hasn't been one issued, but a lot of people are doing it within a square canvas, that way if it has to be scaled down , it'll be scaled equally.
If you already finished your set of content, you can look into adding more material (image or video) or creating more entries with your fam members.