December will see a number of Tiara events.
The Dutch Royal couple will pay a state visit to Suriname next week and the German president to the UK.
A week later the Swedish Royals attend the Noble awards ceremony and the dinners afterwards.

Any predictions for those events?

For the state visit to Suriname I'd love to see Maxima with the Ruby Peacock parure but I think it will be the diamond bandeau if she wears a tiara at all.