I am planning to drive from Chicago to Portland this coming December 25, 2011. I feel nervous of the trip since it is my first time to drive across the country. Which route will be the best one in winter? I read a lot of posts and it seems to me I-80 then I-84 is a good choice. But am I capable to drive through those mountain area with my toyota rav4 ? The suv is in good shape, but I don't have experience with snow condition. please give me some tips and advice thanks.