Should I fly or drive to Tahoe?

I'm attending a business conference in December out in Tahoe, NV, and I'm debating on driving or flying. I have no idea what the road conditions are like out there, but I trust my car on the Utah mountain roads during the snow season, as long as it's not actually snowing the day I'm driving. Sooo, I'm leaning towards driving.

The costs seem to be about the same. At the current gas rates, I get about 400 miles to a tank, and it's about 15 gallons. 1200 miles to Tahoe and back, that would be 3 tanks. 15 gallons is about $30.00 at the current gas rates, so just for gas, it would be $90. Double that number to account for general car use, under $200 to drive. Airline tickets are now under $200, but only to Reno (not Tahoe). I'd have to probably get Long Term Parking for the week ($6/day for 9 days = $56), and a shuttle from Reno to the hotel is about $60.

So I think they're about the same cost, driving or flying, but really it's the roads that would be the determining factor...