Go with the studded tires and don't worry about the frame (my steel commuter) has 6 years of year round riding and not a hint of rust. Components such as: chain, chainrings, cassettes are another story (necessitating yearly replacement in my case). I find that bottom brackets and pedal spindles need more re-greasing in winter conditions as well. Also, rim brakes get clogged with ice/snow and rim brake surfaces take a real beating too. Other than that, 700c series tires do just fine in snow.