The fastest, most direct route from NYC to Seattle is I-80 to Chicago, around the western suburbs on I-355 and I-290, then I-90 to I-94 through MN and ND, rejoining I-90 in MT for the rest of the way. However, do keep an eye on the weather and road conditions and be prepared to modify the route on the fly if necessary. You will have plenty of options if an early season storm decides to show up. Bring a wifi-capable laptop. All the states have current road conditions on their Department of Transportation websites, and weather.com is very helpful for current weather conditions and forecasts.