Theoretically it's just over 2 hours but with any traffic [and you'll always hit something leaving LA or coming into downtown SD] it will take closer to 3. Newport Beach is about 2 generally.
You've got a great week for weather here... warm but not our usual mid 90s.
My heat escape tip: The grand california hotel [located in downtown disney with a direct gate to california adventure] has a great big lobby and both a full service restaurant and cafeteria. Lots of a/c, great ambiance and a nice way to escape without driving all the way back to newport.
Hear you on the doing things at Disneyland a few times... With the summer crowds the kid rides are of course taking the brunt of the lines but from my visit last week it really wasn't too bad [not that I stop in that part of the park but glancing by]. Fireworks just went off and peaking over the balcony looked good as usual...