What would Fred write in a letter to Scrooge telling him to join in the Christmas spirit?

Fred is Scrooge's nephew. His mother, who is deceased, was Scrooge's sister. Family is important to Fred, who has a wife and children. They have a sumptuous family Christmas every year and always invite the uncle. Fred wants to include him in the family celebration, apparently for his mother's sake.
Fred acknowledges but can't really hold Scrooge's rudeness against him. Calling his rather unpleasant uncle "a comical old fellow" who is apparently suffering in some way for past misdeeds, Fred feels sorry for him but still tells his wife, "I couldn't be angry with him if I tried."
The story shows Scrooge's change over several days. Fred thinks his words and repeated invitations have had an effect on him, unaware that he is tormented by ghosts and coming to terms with this haunting.
We also learn that Scrooge routinely declines their invitations, and "rails at Christmas," yet Fred keeps inviting him.
Given all this information, it seems like Fred might need to change his approach. Since he knows his uncle dislikes Christmas--or at least says he does--how could Fred appeal to his uncle?
Maybe including other family members in the process would remind Scrooge of the importsnce of family. Perhaps Scrooge would respond better to an invite direct from the children, if we believe he was once close to his own sister. Or he could offer to feature his uncle's favourite dish on the menu.