I don't want to add to your desire for a Subaru, but seeing as you live in Boston, you'll appreciate this story: I used to live in Concord and worked in Cambridge. One winter afternoon we got a huge snowstorm and all the businesses in town shut down early. I hit a big traffic jam on Route 2, on that big hill that you hit after leaving Cambridge (which is actually the rim of an ancient volcano), where there were dozens of cars stranded, unable to make it up the hill. I put my Subaru wagon into 4WD and carefully snaked my way around them and got home in 35 minutes. One of my housemates with a regular FWD car had left work around the same time and it took her 4 hours.
That said, there are much cheaper 4WD alternatives than Subaru -- even the Toyota Matrix comes in a 4WD version, although it's a bit underpowered. I've been driving a two-wheel drive Matrix since 2005 up here in snowy Montréal and it has performed very well.