i'm going to way in here, yes they are similar, yes winter helps but drift as D1 style is very different, your not just powering over to let the car slide on ice, your entering corners with the car already in position and maintaining that throughout with throttle control etc, on snow its more a power over, and you have to watch out for understeer.
Also what people dont think is when you let off on ice your car slows down, if your in a high speed drift on pavement with the tire spinning and you let off, then the tires grip and the car shoots forward, if your not ready for it is a good way to crash.