Mix in family functions and weather problems, and this time of year can be full of holiday fiascos. But fear not. Instead, take note from Clark Griswold in “National Lampoon’s Christmas Vacation” on ways to avoid the holiday chaos during these last events of 2017. Outdoor events can come with a slew of unexpected problems—one of which includes uninvited local wildlife making an appearance. The Griswolds, for instance, get a surprise visit from a rambunctious squirrel hidden in their Christmas tree.