This page lists all of the episodes in which Christmas is the main theme. Usually, the entire episode has a Christmas theme, except Xmas In July, where it is almost exclusively confined to the main plot segments.
“Harold Green returns to Possum Lodge to spend Christmas with Red and the other lodge members...A Very Merry Red Green Christmas
“On the hottest day of the summer, Harold decides to make Possum Lake a Christmas-themed tourist...Xmas In July
“Red, Harold, Ed and Dalton try to prepare Possum Lake for the Santa Claus Parade. Cast (in order...A Lot Like Christmas