Why are you going through all the hassle of calling Subaru, trying to get it towed, etc?
Have you tried to jump start it yet????
It's obviously a dead battery, and yes, with the changing weather, even new batteries can drop a cell and fail. Jump start it and see if it starts. You can even just take out the battery, take it down to the nearest Autozone or auto parts store and have them test the battery to see if it's good (even then, sometimes they can pass, when they're really bad). If is indeed a bad battery, jump it in the morning, and drive it down to the dealership and tell them the battery is no good.
I'm not sure how savvy you are with cars, so read the jump starting guide in your owners manual and follow those precautions, but mostly, just connect the positive on each battery (the jump vehicle, and the dead vehicle), then the negatives. Always start with the jump vehicle first. Depending on how "thick" the jumper cables are, you should get immediate life out of the dead vehicle. If not, give it a couple of minutes, then try starting it.