Nice to ssssssseeeeeee you again. First thoughts on "Cold War"
POTENTIAL SPOILER ALERT: You have been warned! Interesting twist to the return of the Ice Warriors. Armor!
The TARDIS Translation Circuit seems a bit far reaching in this episode. That it functioned from the other side of Earth, given that the Soviet sub in which "Cold War" takes place was at the North Pole and it (the TARDIS) had relocated to the South Pole just after the episode began by way of the H.A.D.S. (Hostile Action Displacement System) was pretty amazing. More than amazing, in fact quite unbelievable was how the TARDIS Translation Circuit translated Russian into English BEFORE it arrived on the sub! The opening scenes would have been far more believable with English subtitles and Russian speaking actors.
That Professor Grisenko (who was brilliantly portrayed by David Warner) believed a mammoth was encased in the ice which in fact encased Grand Marshall Skaldak seems a bit silly. Mammoths were quite large, sometimes 13 feet tall at the shoulder. I don't believe the sub would have accommodated a full grown mammoth, let alone a tomb of ice large enough to keep it frozen for the duration of the return trip. It would have been a simple script edit to indicate that what was in the ice was an immature mammoth but that's not what were were led to believe.
Otherwise a rather good episode.