Depending on how tall you guys are, you can put bikes upright in the Matrix. Mine fits fine, my DH's has to have the seat post either lowered or removed. If neither of you are tall, then they'd fit no problem.

VW TDI wagon might be an option too. 5-cyl but gets ~40 mpg diesel. Lots of room in back but I don't know about the upright bike thing or not. Most VW's do pretty well in the snow, so I can't imagine that the sport wagon would be any different.

I like the Subaru's but they really need to work on their gas mileage. We considered an Outback but found the MPG really disappointing and removed it from our list.