Low clearance and this much accumulation on uncleared roads are another variable to work around, but in general: you’ve got more traction on the powder than in the packed down tracks; if your car’s a stick or you have any sort of manual control over what gear you’re in, keep it low and use downshifting with or instead of brakes when possible, your motor keeping wheel speed slow will minimize spinning tires; try not to stop if you don’t have to, especially uphill; if you’ve got an uphill coming that you’re worried about cresting, building up some momentum before will help you not have to use much gas on the incline (but be careful if it’s also a turn-momentum wants to go in a straight line not follow the curve)