You cannot ever avoid offending people, the idea is to make sure to offend the right people.
I know people of different faiths, and have yet to hear anybody of any different faith say that they are offended by Christmas, the Christmas season, Christmas trees, or any other symbols of Christmas or Christianity.
Granted, most people I know are conservative, not liberal, however, it leads me to believe that this business that non-Christians are somehow offended by Christmas is nonsense.
I think that the LEFTISTS think that non-Christians SHOULD be offended, because the LEFTISTS themselves are offended by religion in general, and Christianity in particular. So the left puts out this offended crapola and says they are speaking for non-Christians. If we are intimidated by the left, then this becomes the public narrative.