I've made this ride to Oregon many times and know all the routes well. First; it is important to check the weather.....it may determine your route.
I-5 is fast, boring and loaded with semis (it can also be HOT, HOT, HOT). 101 is more interesting, but will take longer. 1 is fantastic, but takes a long time and is often fogged in. 395 is also very cool, scenic, memorable, but long (Lake Tahoe).
If it were me...... I'd take 101 all the way to Crescent City (San Francisco, the redwoods, etc.) and then take 199 to Grants Pass, Or., 62 to Crater Lake and 97 to Bend.
I-5 above San Francisco is fine and would save you time. Also gets you close to Sacramento if you want to stop there.
I tend to be like a stable horse, once headed toward home.....I want to get there fast, so I try to take more time getting there and less time coming back.
The best I can say about LA is that you can get in the HOV lane.....405 to 101.
Good luck and have a great trip.