I used to commute from Thousand Oaks to Huntington Beach. I left at 5AM and there was no traffic; I did the 72 miles in 65 minutes (or exactly one bladder distance away...).
Check out
Sigalert.com Los Angeles Traffic Map during the time you expect to commute. See if there any routes that are better than others - even if they are less direct.
You can get a feel for tomorrow's traffic right now by using google maps, traffic, traffic at time and day. Set it for 6AM during any day of the week (fridays are usually a little lighter).
Finally, I think your afternoon commute will be worse than your morning commute.