I am planning a roadtrip from Denver to LA over the Christmas holiday---Would it be best to travel further south via I-25 and I-40 or take the more direct route via I-70 and I-15 ?? I have a 4 WD Jeep Cherokee, but have never driven in the mountains during the winter months. How much time should I allow for this kind of winter travel? I am assuming that these interstates are very well maintained during the winter and suspect closures are usually 24 hrs or less after winter storms. Thanks for any advice.