12-18" of snow is a bitch to traverse even with a 4x4. I have grown up in snow my whole life from 4" snowfalls to 14-18" ones. Driving 30 miles in that amount of snow is unwise during the storm and shortly after wards.
If you drive off into a snow filled ditch you might find yourself in 48" from blowing and snow plows. I know because I have been there before int he past, 4x4 didn't get me out that day a $70 tow fee the next day did. Walking 4 miles down an Interstate to the nearest interchange in blowing drifting snow after dark, with vehicles going in the ditch all around you isn't a whole lot of fun either.
I drive 17 miles one way to work and 1-5 times a winter I reconsider driving, or attempting to be at work on time because my well being isn't worth the paycheck.
All a factory 4x4 does for you is make driving a little easier for you in wet, muddy or snowy conditions, still takes just as long to stop and just as long to get some place as a 2wd vehicle.
