It appears that the common thinking is to put real snows on all four wheels. In addition, the rear 19" wheels should be changed to 18" and in the same width as the fronts. In other words you loose the stagger.

I plan on buying 4 18" wheels with Bridgestone snow tires and running them for the winter months.
I will just lay up the Pilot sports on their OEM wheels for the winter.

In addition, I will place a considerable amount of barbell weights or sheet lead in the rear hatch to put more weight on the rear tires.

That should do the trick. This will probably run about $1600 when all is said and done. (ie: four rims and 4 new tires).