First, awesome story - congrats on taking your wife through hell to get her to deliver at the hospital. If you get pregnant again due in the winter, may I recommend learning about home delivery
The odds of a complication are far lower than the odds of a travel-related issue in those conditions! Holy cow! Way to go man
Second, you should send your story to tirerack. They chose that tire and recommended it for your needs and size and I am confident the car would not have made it with BMW's recommended setup (which is a performance minded setup).
Third, this story is the difference between a "winter" tire and a "snow/ice studless" tire. Those are conditions where an SUV rocking good all terrain tires would struggle mightily.
Lastly....a note on the complainants. My last vehicle (besides an e39 m5) was a 6,000 pound SUV with front and rear locking differentials (stock), an air suspension that could raise and lower the vehicle >6" (stock), great gearing for snow (diesel), and very good all terrain tires (Toyo). And it was dangerous in winter...the combination of all that weight, non-winter tires, an extremely heavy engine, and a much higher CoG made it truly a bad vehicle to drive around other people. It may have been able to forge through 2' of unplowed snow in a mountain pass - but that doesn't mean it would be a good vehicle for lots of stop signs and vehicles all around me.
I sold my e39 m5 and that SUV and bought an f80 m3 and a set of winter tires. The low center of gravity, good weight distribution, rear diff, and the right tires makes it a much better vehicle. I drove my wife to the delivery center in it last October and drove our newborn home in it.