While this route is pretty simple and easy to follow, it will still take you a little over 10 hours to drive between the cities. This means that you’ll need to spend the night in Portland at the very least—and you may want to stop on the way there and/or the way back.
While the frequency with which you stop is totally up to you, it’s typically recommended that you drive eight hours at most in one day of a road trip. If you do decide to stop for a break, the halfway point between San Francisco and Portland is Medford, Oregon.