As has been said, place your priorities in this order:
1 - Snow tires
2- Driving technique (smooth, fluid movement and driving within the conditions and limits of the vehicle)
3 - Drivetrain
Snow tires offer about 40% more traction than all-seasons. This means that if you need to stop in an emergency, the snow tires may easily mean the difference between stopping or crashing. 40% is a HUGE difference.
Driving ability is the next most important factor. Become smooth as silk in your steering, braking and throttle inputs. Recognize how the rules of physics are greatly accentuated by snow and ice and get a feeling for where these thresholds are in your car in a safe environment (empty, obstacle-free parking lot is a good one. Do it smart and safely and keep in mind that while it is a learning experience, the police may not feel that way). Knowing your cars limits makes it easier to stay within them and also makes it more likely that if an emergency situation arises, that you will react properly rather than panicking.
Your vehicle's drivetrain layout is the least important. I owned a FWD car with snow tires and it was a beast in the snow. While I am a Subaru convert, if I had to choose between a FWD car with snow tires in the winter and an AWD with all-seasons in the winter, I'd choose the FWD every time. That said, AWD with snows does admittedly trump everything.