In that scenario USC would go to the Foster Farms, Washington State to the Sun, and UCLA in Vegas leaving BYU likely in the Hawaii Bowl. This assumes Alamo takes Oregon as the higher ranked team (which is likely). It is possible that Alamo takes USC and Holiday ends up w/ Oregon which frees up Foster Farms to take UCLA.

If USC beats Stanford then Stanford in the Alamo, Oregon in the Holiday, UCLA in the Foster Farms, Utah in the Sun, and Washington State in the Vegas. If Stanford makes playoff then Oregon in the Rose, USC in the Alamo, Utah in the Holiday, UCLA in the Foster Farms, Washington State in the Sun, and Cal in Vegas. If USC beats Stanford and Stanford sneaks into the Fiesta then you'd have Oregon in the Alamo, Utah in the Holiday, UCLA in the Foster Farms, Washington State in the Sun, and Cal in Vegas.

The takeaway is that there are 3 teams that look to still be in play for Vegas: UCLA, Washington State, and Cal. If 2 P12 teams sneak into the NY6 then it will be Cal. Otherwise it could be either UCLA or Washington State. If I had to handicap it I'd say probably 50% chance that it's Washington State, 35% chance UCLA, and 15% Cal.