You might want to avoid Donner Pass on I-80. Chain requirements are common.Try this route:http://maps.google.com/maps?f=d source=s��You can check highway conditions here:http://www.dot.ca.gov/cgi-bin/roads.cgior call 1-800-427-7623
Go up I-5 to the Sacramento Airport off-ramp, park in the long term lot and take the shuttle to the terminal.
try to avoid Colorado.
not a good idea because if it snows they close down the roads for hours untill they clear the snow
check google maps terrain and turn the live weather button on.