Our family drove down to DL in early Feb this year for 15 days total down stateside. The I-5 is the fastest route down. It took us 3 days to drive it, and the kids were fine with the drive. If you have BCAA, get the maps and the hotel books. By using hotels that gave BCAA discounts it saved us a good chunk of money. If you have the time, it's worth driving the coast and visiting the Monterey Bay Aquarium. But the roads are very windy, so that you are aware of it. Have a great day!
Trish