I would add that in addition to winter tires, experience in driving in snow is a must. It doesn't matter what kind of SUV & winter tires you have if you don't know how to drive in snow -stay off the roads until it is gone!
A few years ago we had a family move into our subdivision from Victoria BC (born & raised). Mr. had no experience driving in snow so he immediately went out and bought a big SUV with snow tires at the first snow fall. Our subdivision is at the top of a ski hill and you cant go anywhere without going down hill. On his way to work Mr. did a 4 wheel drive skid right off the road and down the side of the hill the 2nd week he had the vehicle. He was so far off the road the tow truck had a tough time winching him out. He just kept saying "but its an SUV & I put snow tires on it"!

Just slow down! Just because the speed limit is 50 doesn't mean you can do 50 in the snow!
~Diane