Christmas Around the World (Doctor Who: Short Trips)

My memories of this one are vague, now-- but that speaks to something in and of itself; I still remember bits and bobs from Short Trips: A Christmas Treasury and The Ghosts of Christmas. The linking theme here is too specific but too thin, i.e., it locks the stories into a range too limited to consistently yield something interesting. I don't really recall any duffers, but many of them just aren't long enough to even be bad. The memorable strong stories were Gareth Wigmore's "Mirth, and Walking Spirits" (a lost Antarctic expedition celebrates Christmas), Eddie Robson's "Interesting Times" (the third Doctor and Sarah Jane in the Vietnam War), and Andrew Cartmel's "Christmas in Toronto" (surely the only worthwhile thing Cartmel has ever written for Big Finish).