I'm back.
I did what a lot of people were saying. I used ABRP for planning, then put the next charger into Teslas navigation. I also found I was being way too conservative and got much better accuracy using actual numbers. took ~30min of steady 65mph driving to see my Wh/mi is ~278.
Since I had a long trip, I also did it at 75, 77, and 80 (30mi each).
Numbers for MYLR7+AB with about 300lbs of cargo and ~3500mi on the odo
65 was 277Wh/mi
75 was 309Wh/mi
77 was 319Wh/mi
80 was 345Wh/mi
I probably stopped once or twice more than I'd have liked to for charging, but it wasnt a hassle. 20min goes by so fast. All the stuff I brought in preparation for waiting was a waste. No need to break out a camping table, no time to watch videos or play games. By the time I went to the bathroom, cleaned out the car and put in the next waypoint it was practically time to go.
Looking forward to the next adventure. Will definitely travel