It always astonishes and saddens me when I read of people taking down their trees and decorations, sometimes as soon as today. If not today, certainly before New Year.
All my life - both here and in Canada - Christmas has stayed until 12th Night (January 5th or 6th, depending on your viewpoint; we do January 5th) and it gives you a chance to get used to the idea!!
That said, we generally put everything up later than you do, so I guess it sort of balances out........sort of!!!
Because it's already done in so many other countries, just say you've decided to join the international jetset and observe their customs of Christmas!!!!!!!!