I made the Vancouver - SLC drive too many times to count when I was living there, and it can get pretty hairy where the 82 becomes the 84 in the winter. If the weather is good, you can do it in about 16 hours. I used to straight shot it on a lot of caffeine and slim jims
Just be careful coming out of Oregon into Idaho. Lot of downgrade and possible ice - plus the cops love to wait at the Oregon border where the speed limit drops 10MPH!