I live in Philly and work in Wilmington, so I'm in the same region. The best approach would be a separate set of winter tires, but if you don't have the space for them, you could switch to a good set of ultra-high performance all-seasons to use year round. You wouldn't want to drive in anything but light snow with those, but with the minimal ground clearance of the FR-S, you wouldn't want to anyway, regardless of tires. In my FWD cars, I've been fine with all-seasons in our winters. Frankly, I think the balance of a good RWD car can be an advantage in slippery driving if you know how to use it, and you have lots of excellent advice in this thread on that.