A Word Of Caution: As We Always Say, Look In The Owner's Manual.
Cars have differentials that allow the drive wheels to spin at different rates to prevent the tires from scuffing, especially while turning. Also, they equal out the torque delivered to both drive wheels. So if you have one wheel spinning on ice / snow, the other one that is not stuck doesn't have the torque to move the car, and there you are, stuck in one place.
Most regular 2-wheel drive cars have this type of differential that lets one wheel spin if it's on ice or in the air. The problem here is that the speed of the ring gear in the differential is the "average" speed of the two drive wheels or axles.
So if the gripping wheel doesn't turn and the non-gripping wheel just slips and spins, it can turn at twice the speed indicated by the car's speedometer. When the speedometer says 60 mph, for example, one wheel may be turning at the incredible speed of 120 mph! That's just at an indicated 60.
That 120 mph exceeds the speed of even some "speed rated" tires, such as "S" and "T" rated tires. Many tires are not speed rated and often recommend a maximum speed of only 85 mph!
This high speed is bad for the car and can explode a perfectly good tire. My car's manual warns not to exceed an indicated 35 mph while stuck or you can explode a tire or damage the transaxle.
Many people carry sand or kitty litter in the winter to help get traction when stuck.
This whole warning about excessive spinning that I've written may not apply to this AWD Outback. Cars with limited slip or locking differentials can be an exception. The owner even says that his car can send more torque to different wheels when needed. Maybe somebody can explain how this Subaru works. Maybe somebody can check their manual and tell us what it says.
The best thing the owners can do is to read the Owner's Manuals. They usually cover situations that pose a danger to the vehicle and its human friends.