Can't speak specifically about DFW->LA (looks like 1,400 miles), but in my Tesla I can do Denver to Wilmington with 0 overnights, sane, as a solo driver... 1,800 miles. Precisely
BECAUSE of the charging, I can get in a "power nap" while charging, doing the recommended 25 or 50 minutes to fit with sleep cycles. Usually around 24 hours in I need to take an extra 50 minute nap in there.
Again, it really depends on the individual. This works for me.
As far as leaving the pump goes, I was painting a picture of some of the "death march" drives I've done, didn't necessarily say I was solo. I, personally, wouldn't leave the pump while pumping, not because of theft but because, you know, of the spewing of gasoline if something went wrong.
As far as your original point... I've done that math multiple times, I have 2 gas cars and the EV, and continue to pick the EV over the ICE. But, again, that will vary by individual. My personal experience, coming as a gearhead who has taken quite a few non-stop road trips both solo and with others, is that the EV for long trips (I've done 5-6 1,800 mile trips in it), are better in my EV than ICE cars, and that's with 5 year old tech. A current Tesla will have fewer, shorter stops.
Your speculation is perfectly valid, of course. Doesn't sound like you've had an EV, which is why I call it speculation. The point I'm making is that I've actually had that choice, 1,800 mile trip where I can take a EV or a ICE, and I've chosen the EV on multiple occasions.