You got some good advice here. I second that you use your sway bar.
Just keep things steady up and down the hills and take your time. Don't let the transmission hunt between gears such as 3rd and 4th gears but put it in the lower one and lock out the overdrive.
Going downhill, use a combination of your engine and brakes. Dave's point about using the brakes too much is important. You want to avoid overheating them so don't ride them.
So, you'll figure out the best combination of gearing and torque to get up the hills and the best combo of gearing and brakes to get down safely.
Have a great trip.
DW, 3 Kids and our Goldens
2012 Shamrock 233S
2008 Toyota Sequoia 5.7L 4WD