Looks like you have all the bases covered. Smart thinking.
You need to pack some jumper cables, misc tools in case you need to fix anything along the way, and a reserve gas containe, filled of course. Also, get some road flares if you don't have any.

If you're driving straight through or for long portions of time, try not to eat heavy foods i.e, junkfood so you don't get drowsy and or have to stop and use the restroom unnecessarily. Also get an extra battery for your cell.