Why wait .... set up a dirt bike with ice tires, hook up with a group that regularly ice races (on roadcourse type tracks not ovals) and get to it! YOU WILL GO FASTER next year on asphalt because of it.
I just heard the testimony last weekend from a friend that raced against my son, "Jr. was fast but not real fast until he started ice riding, after a season of ice racing I couldn't get near him".
You owe it to yourself to get out there. It is the best off season training you can do.