Have you experienced winter conditions taxiing a large transport? If not, you should know that in some conditions, the airplane will even "sail" in a strong enough wind...(but not usually in the direction one wants!), and the only way out is to call for the tug, if it can reach you without sliding off the taxiway itself! ;-)
Indeed. I once saw a parked, uncrewed B-52 (490,000 lbs as it sat there) moved 20 ft backwards and 10 ft sideways (and turned a bit) by a line squall that combined freezing rain with high winds. There were a lot of guys walking around that one shaking their heads.