AZ to NC roadtrip for waterfalls/fall colors

Hi everyone first post here, and first roadtrip. I'm renting a campervan (17.7 ft) to drive from Phoenix AZ to the southeast to see fall colors with my boyfriend and cat. It's hard to time when leaves change color but we want to visit a place around georgia/north carolina/south carolina/tennessee and do day hikes. We're leaving October 23rd and will be back November 4th. So we should be at the destination the 27th-31st. Looking for route advice and/or hiking suggestions if you have any. We thought this would be doable since I have always wanted to see the waterfalls/fall colors of southeast US and it's our first vacation in a few years so we're trying to go for it. Feel free to be honest if you think it's a bad idea for the time frame, open to stopping in a closer destination but we are trying to see the waterfalls/fall colors of southeast US. we will be sleeping in the van(it has a bed) and it fits in tent sites so don't need an rv park, so rest stops/parking lots/ ideally free campsites where possible but the van isn't 4-wheel drive so can't go too off-road. Will be cooking the whole time, it has a stove/sink/mini fridge.
Also taking the cat because she's fine with leash and harness, doesn't meow in the car and doesn't like being alone for too long. i have a cat backpack to carry her in or she will stay in the van.
Originally I wanted to go to asheville but I did research and as far as I'm aware, it's going to be past peak for fall colors at mid-high elevations so researching low elevation areas in the southeast, smoky mountains that will be pretty when we go. really looking to do some hikes and see waterfalls/fall colors, its a nature centered trip.
As for the route, does anyone have advice if the I-40 route or I-10 east route is better? Some other threads on here said I-10 e route is better because it's flatter. I would like to take the I-10 east route except for one concern I'm trying to see if it can be worked around. A portion of the I-10 e route goes literally along the mexican border, and that makes me nervous because my boyfriend is DACA(born in mexico), so even though he's here legally and has his IDs/documentation, i've heard of people with daca getting sent to detention centers by ICE and I'd like to avoid the border altogether. any suggestions for routing around that area?
Thank you in advance for any input!

Welcome to the RTA Forum!

As far as routes, personally would take I-40 one way and I-10 the other, because the distance isn't much different. Going along the border itself wouldn't be a concern, however, I do think their may be a border patrol checkpoint or two along I-10 in NM or TX. Noting the current climate, if you wanted to avoid the potential problem, sticking to I-40 might make more sense.

Your timeline works, but doesn't leave much room to spare. The biggest concern would surround the rental of the van. You're probably not going to be able to hit the road right away when you rent it. I presume there will be a fairly lengthy, but important, tutorial about how to use the vans systems. You'll also then have to pack up the van with anything you're bringing with you, including food, sheets, the cat! I also presume you'll have to return it at a specified time. Right now, it seems like you're giving yourself 4 days each way for the drive, which is really about right for the amount of time you need. But if your first and last days are really half days or less, then you're starting to get a little pinched.

Speaking of the van, while you've got a stove and sink, what will you have for power and water? What about a toilet? That might be a limiting factor when it comes to free camping, if you need to plug in for power, or don't have a toilet on board, or if you do, have to find a place to dump your waste, those things need to be considered. A truck stop parking lot also might be less than idea when factoring in your cat.