I've used evtripplanner too. In 2016 I used it to plan my route from MA to CA and back, after scheduling a Tesla factory tour. I printed out a bunch of pages and charts, with charge times and how many miles I needed to charge up to at each supercharger to minimize my travel time. Mostly I didn't use my charts, and ended up skipping a few chargers - after striking up conversations at superchargers, I often left with many more miles than I needed.
I was alone, and slept in the car. I used some lawn furniture mats to level the back with the seats down, and used a sleeping bag. When I needed a shower, I found a state park with a campground and used the shower at the restrooms.
I travel with breakfast cereal, a small cooler with a quart of milk and some OJ. I refill the cooler with ice from a hotel while supercharging, and keep a couple bottles of water in there. The case of water usually sits in the front trunk "microwave" area that my classic has.
It was a fabulous trip: Hoover Dam, Death Valley, Yosemite, Pacific Coast Highway, Yellowstone, Mt. Rushmore, Badlands, Niagara Falls... I took 2 weeks off work because of timing. I wished I had 3.
I enjoyed my trip that year so much, I was looking for an excuse for another road trip. The 2017 eclipse was the catalyst. This time I did no preparation for the routing at all, I only printed out maps of where the eclipse was going to occur. My destination was to be determined by keeping an eye on the weather, looking for the least cloudy area. I headed west, and after a day had driven from MA to OH, and the weather indicated it wasn't worth going any further west; so I spent a day at the National Museum of the Air Force near Dayton (which I stumbled on), then made my way down to TN.
This trip confirmed that you don't really need to do too much planning with the supercharger network built out as it is. (Aside from ND and a few other exceptions, of course.)
As long as you're not in a critical time crunch, it's no problem at all. I don't even have NAV in my car (no "Tech Package"). I just clicked on a supercharger on the map which gave me straight-line distance, added 50% or so to that and made sure I had at least that many range miles before I left. In the summertime, I usually beat the rated miles driving at posted limits; even with AC. The extra miles gave me the freedom to take side trips if I saw something interesting, and cover for elevation changes or poor weather.
For me, it's pack some clothes, water, breakfast, some apples to munch on (I found that if I open a big bag of chips it's half empty before I realize it), and just drive.