The LaCrosse is my least-favorite Buick. They are very hard to see out of.
I am surprised to find that you can get a 2010 or even a 2011 CTS in your price range. I'd try not to go older than the 2010. Great looking cars. I'm not sure how well this car suits your practical needs, and they're not the quietest, though. A wagon was offered the first few years, but I see none in your price range.
I wasn't aware that the Terrain was much quieter than the Equinox. I'd decide between the two based on styling. They are quiet and smooth-riding. Reliability has been much better for those 2012 and newer than for older ones. The problem this is that it's hard to find one that is 2012 or newer within your budget.
The car I actually like best for your needs is the Ford C-MAX. It's a hybrid, so it'll do quite well on gas around town, especially if you adapt how you drive it (gradual braking wherever possible). Great visibility, good rear seat and cargo room, good ride, and quiet. I really enjoyed driving the one I had for a week (review in the "more about" link beneath the photo). AWD isn't offered, but there's a little more ground clearance than in a regular car and a lot of weight over the drive wheels, so it will perform significantly better than your Civic in the snow. After a rough start, they've been doing better recently in our reliability survey. Finally, you'll find quite a few 2013s around with prices around $15,000.
The #1 thing against the C-MAX is it is much less pretty than the CTS.
The related Escape is more attractive, higher off the ground, and available with AWD. But it's less efficient, not as easy to see out of, and I didn't enjoy driving it as much. This said, it might also be worth a look.
I compare the Escape and Terrain in my review of the GMC.