Have you considered the train?
It'll take 100 million years (ha, OK, 24-36 hours if memory serves), but especially if you get a roommette it's nice.
I suggest it mainly b/c of all the pitstops you'll be taking (by the way, blow some of that baby dust over my way, OK???? thanks!), which are going to slow you down. And cars weren't comfy for me by that point.
I did take the train down to the bay area in mid-March when DS arrived in late May. I had a roomette, and having that makes you "first class" automatically, which means your FOOD is included. And you have a special lounge car to lounge in.
Now by that time, when I was in my roomette all made up for sleeping, I could stand with the backs of my knees touching the bunk and my belly would touch the door...made the late night bathroom trips interesting!
Then again, for you guys you'd need either two roomettes or one of the bigger rooms (only 2 people per 2 bunk roomette), so you might not have that problem.
Anyway, it wasn't peaches and cream...it's interesting walking down a moving aisle when your balance is off anyway, and I developed a protective way of walking so I would hit a shoulder instead of belly if the train lurched, BUT even with all the difficulties, I preferred that to the idea of driving all that way.
Good luck!
) we are about 5 hours north in Washington. We have driven it twice. We took I-5 the whole way. It took us 23-24 hours each way, but we didn't stop at nights, so that is basically straight thru except for food and potty breaks. 
!
