If you stay on trucker routes you are good pretty much all year. Of course you have to watch the wx closely. Every state pretty much has the 511 number for highway closures. Pass closures etc. If wx gets bad we pull over at truck stops for a few hours or the night. They work hard to keep the truck routes open in the winter. All that said. Do not leave a standard truck route even if it seems shorter in the winter. If you are on some low traveled secondary road you could get in real trouble in the winter.