If anything you want higher gears in order to minimize wheel slippage. In an automatic, you would be told to start off in 3rd. In a manual, same deal.

You probably need snow tires. CVT will eventually go to a higher gear as wheel speed goes up, you just need to release the accelerator to give the car a chance to track over snow.

But if it's icy, you have no chance unless you had a good set of snows on.