Keep reminding yourselves that a long trip is just a series of shorter ones.
Is there a set timeframe, or just basically take as much time as needed?
I have mixed feeling about interstates. They're great time savers for getting to a destination, but no doubt little things along the way will get missed.
Generally I'm ok with missing the minutiae of a long drive, since my time is limited, I elect to spend it on my destination.
My recommendation is take some spare parts and do a thorough check on everything before heading out.
Worst part of a long trip I've had in years past was a broken spring and the repair shop pretending that there's no internet, taking four days to get a replacement in. Next trip I undertake that's more than 1000 miles, an extra spring and hangers will make the trip too, not that I expect to need them.