-Ice skates: found in skating lakes or in civilian homes serve to move around on ice with greater efficiency and speed.
-Ski-
Found in ski areas in the mountains serve to descend snow-capped mountains much faster.
Snowboards
Found in the same places as the but rarer skis descend much faster but has the advantage of being more efficient to deflect obstacles.
Cable car
Connect the hotels the ski slopes and snowboards take up to 4 players at a time, are better and safer to return to the hotel because they follow a straight line so there is nothing to worry about the low visibility in heavy snowfall.
Bonus suggestion: Indigenous NPCs.
They survived thanks to their large groups and knowledge of medicinal plants, live in leather huts in the plains, provide fish, meats, natural remedies, and bows in exchange for something or some mission and service, as well as being able to trade items for wild horses very fast.
Horses aren’t indigenous to the tundra, and most “indigenous peoples” are fine with using modern medicines, firearms, automobiles, and power tools. They would have no more and no less reason than any other survivors to learn bushcraft, study local flora and fauna, or to salvage and repair modern technology.