I got 25 mpg right out of the factory on the freeway. I'm getting about 26.5 mpg with 2000 miles on it on the freeway. My averages have never been higher than 23 mpg. Haven't had my out in the snow yet, but the snow handling will be very dependent on the tires you put on.
With 25,000 miles and one minor snow season, I see ~ 24.5 - 25.0 mpg round trip averages for 35 mile (each way) commutes. I see up to ~ 30-31 mpg @ 70 mph on level freeway, A/C on, 17" wheels with Sport Velocee tires @ 38 psi, average outside air temp 75-80 deg. The tires / car were not all that impressive for minor snow amounts - I strongly recommend you look into purchasing dedicated 16" steel wheels with snow tires for that portion of the year when you expect snow. I had to leave the car at the bottom of the driveway due to the slope covered with a few inches of snow - same conditions, our 4wd Suburban ate it up (M&S tires). Hope that helps. Pk