Thanks everyone for the advice so far! I appreciate all the info and tips I can get, especially since Highlander hybrids are not a common overland vehicle. I've been busy reading the operation manual and scouring the internet trying to learn as much as I can about the Highlander's systems so that I can safely drive it to its' best abilities. My current curiosity is the "sport mode" drive function, which is basically an automatic car's answer to stick shift... Even though I know how to drive stick, I haven't found much to convince me if using it in off-road situations with the Highlander would be a good thing or not. Sport mode aside, my past experiences driving through Santa Cruz have been great, and what I've been currently learning about the Highlander, I'm now confident that it can take me to many awesome places as long as I drive carefully. I don't plan on doing anything extreme with it anyways, and I don't want to risk reducing gas mileage too much, so I've come to the conclusion that keeping the vehicle's stock parts will be best.
I ran my own camp at Burning Man for over 5 years, and I think that overlanding seems to be very similar to Burning Man in many aspects... The most important lessons I've learned for myself from "burning", and keep coming across while researching overlanding are to plan ahead, be prepared for problems that may occur, choose gear/supplies wisely, create a good organization/storage system, and to take care of the vehicle, especially in terms of tires, fluids, weight distribution, and following the maximum payload specifications. Burning Man and overlanding makes it waaaay too easy and exciting to get sucked into extravagant camp/transportation set-ups, and the possibilities are endless! I've gone the extravagant route before, but I've also done the minimalistic approach, and taking those past experiences plus everything I've recently learned about overlanding into account, I'm thinking a happy medium is perfect for me! I plan to focus on and have fun creating a good storage, kitchen, and tent build instead of spending time and resources on the Highlander's mechanics like I was originally thinking about. I want to camp semi-luxuriously while being able to comfortably fit myself, my husband, and our two Dogo Argentinos (big lazy dogs!) in the vehicle during travel. I may eventually add some extra undercarriage protection and all terrain tires once I start trying out more difficult terrain, but I would rather get out there to explore sooner than later!