You shouldn't be going that fast, when you're driving in snowy conditions in the first place, but using low gears will give you better traction and control. Also, there's a pretty easy way to use your brakes (your biggest snow enemy) much, much less, if you're driving a manual car: downshifting. It's much safer, as you won't risk locking up and sliding. And as a bonus, you're not wearing your brakes as much.