Driving across country in Honda Civic with cat. Cheap as possible?

I have to relocate in a few months to Philadelphia, PA from Sacramento, CA. I will be driving with one other person and my cat in my 2001 Honda Civic. We plan on driving nonstop as much as we possibly can by taking turns driving and sleeping. I will stop in Utah to spend the night at my uncles, sleep in the car one night, and maybe get a motel one night. If an additional night is necessary I was thinking camping or another night in the car. My cat HATES driving. I took her on a 7 hour drive once and she was devastatingly miserable the ENTIRE time. Second time I had to take her on a one hour drive (to move) she pee'd herself because she was so distressed. I'm extremely worried about her. Another alternative, if I could find a cheap way, would be to fly her. Although it would be stressful as well the time would be shorter and would make sedating her easier. I imagine it would also make the trip go as I plan (less stops etc.) any experience or advice with this? I plan on doing this around October/November. Price is a HUGE factor for me. I have a tight budget to the point where I will be skipping some meals to save.

Problematic situation search over google that could actually help

Here's what I did, but only consider this if price indeed is not a huge factor. Leave your cat with a family member or a friend. Do your drive on your own. Fly back to Philly once you are set up in Sacto. Fly your kitty back. It's a lot easier on your feline to do the 4 hour flight as apposed to the 2,800 mile drive.

http://vetmedicine.about.com/od/felinehealthcats/a/Cats-And-Car-Trips.htm