Well, I have the perfect solution for you. You can leave them up until Candlemas Eve (1st February) and tell everyone that you're following an age-old tradition.
As I have mentioned before, it was traditional in Medieval and Tudor times for homes to be decorated with greenery, such as laurel, holly, ivy and rosemary, at Christmas time but there was no rush to take it down on Twelfth Night, instead it was left decorating the house until Candlemas Eve. 17th century poet Robert Herrick wrote in his poem "Ceremony Upon Candlemas Eve":
"Down with the rosemary, and so
Down with the bays and misletoe ;
Down with the holly, ivy, all,
Wherewith ye dress'd the Christmas Hall :
That so the superstitious find
No one least branch there left behind :
For look, how many leaves there be
Neglected, there (maids, trust to me)
So many goblins you shall see."
Of course, you now need to remember to take them down on 1st February otherwise you'll have those goblins to contend with!
Note: Candlemas, which is celebrated on 2nd February, is also known as the Feast of the Presentation of Christ in the Temple and the Purification of the Blessed Virgin. It commemorates the day on which the Virgin Mary would have been purified after childbirth and would have presented her son at the temple in Jerusalem. It was also the day on which Church candles were blessed.