My first choice if you are timesharing would be Oxnard/Ventura. Since you would only be doing graduation, it might not be so bad (which school? The professional schools have graduation on different days). If it is a weekend, the traffic won't be as bad as on a weekday.
Just my personal preference, but I prefer the commute northward from UCLA than south. None of it will be great. Another option if you like the mountains is to get a house rental in Pine Mountain Club. It's not close to anything but is about a 90 minute commute to UCLA (PMC is about 80 miles, but half of it isn't clogged by other cars). They used to be affordable, and the area is very pretty.