Anything will do fine in the snow if you put the proper tires on it. Many of us raised several kids, went on trips to the mountains regularly, towed trailers, and never had AWD or SUVs. We did just fine.

You seem to be focusing on the driving experience and seating position. What will begin to overtake those concerns isn't just the carrying capacity, but the loading and unloading. A higher vehicle will be very difficult for your wife to reach the car seats compared to a lower vehicle, unless she is very tall. Low is good.

Take three car seats to the dealer. Take along three ten pound bags of sugar. Load and unload them, reaching across and securing all the straps. Then imagine the centre child is crying and needs to be unbuckled while not disturbing the other two. Some of us have been through this, albeit not with triplets. Before minivans, we used station wagons, in our case a Volvo 245.

__________________
2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue