Overall experience: Nicest Nor Cal-to-So Cal-and-back drive we've ever done.
1148 total miles, $48 supercharger fees (one supercharger stop: no charge (?!), one overnight camping charge, so YMMV). At the campground, ranger asked where our trailer was...
Two large dogs (Yellow Lab, Golden Retriever--both big shedders): used a hammock seat cover recommended earlier in these forums, and the dogs both were super comfy. Plus a lot (but not all) of the hair/sand was easy to remove regularly by simply shaking out the cover. A quick once over with a 12v vacuum got most of the rest, and after a few minutes with a shop vac back home, she's as good as new.
1) % range at destination estimates were spot on. Even if they dropped initially a bit during the trip, by the end they were within +/- 1-2% by the destination. This was with 2 adults, two large dogs, and luggage.
2) Tesla camping: it can be done, but not too comfortable. Needed thicker pads, but then clearance to trunk would be a trade-off (we used 2.5" self-inflating pads). Pads tended to slide down towards trunk as seats folded down aren't quite flat. Maybe some velcro would solve this?
3) Doesn't seem to be a way to keep power ports & climate on while parked. We could have left a door open, but wanted it to be locked. Climate could not be turned on via the app when less than about 65 miles of charge available, even while plugged in. After sufficient charge, app kept climate going for 2-3 hours, so had to re-turn on climate twice during the night. Looking forward to camping mode if we ever do that again.
4) I got front seat covers for the dogs during camping -- that helped a lot. Also I vinyl-wrapped the piano black portions of the car to protect from scuffing. The dog on the driver seat moving during the night would wake up the car at random times.
5) I should have locked the window controls... one dog opened the window during the night (which was sort of handy, since I forgot to crack a window). But I only think you can lock the passenger windows. Maybe put some type of cover over the driver side buttons.
6) Don't forget to unlock the doors via the app prior to opening the doors to disable the alarm, particularly if the phone key is out and about with someone for a walk. I had experienced this at home while applying the vinyl wrap, so we didn't make this potentially embarrassing error while camping.
7) Bring something to cover the roof glass if sleeping in the car. Not necessarily for privacy (it's pretty tough to see in if the lights inside are off), but to keep any lights outside from bothering you. If camping near the coast, make sure it is water resistant.
8) We took I-5 down to experience the Kettleman supercharger. Definitely a great place to stop and charge. However, well do 99 next time: It's 3 lanes in many places, and lots of 70mph segments. I-5 is 70mph the whole way, but almost all 2 lanes thick with trucks. Traffic gets bogged down passing the trucks, and the crazy people who need to go 90mph ducking in to any daylight between cars makes this stressful. EAP is hardly useful in this scenario, as a distance of even 1 is an invitation for everyone to go around you, and you end up going slower than the truck you are trying to pass as the autopilot backs off the jerks who cut in front of you. Driving on 5 is suicidal, 99 is sooo much less stress: for our route, it's exactly the same mileage, and Google says only 4 minutes longer. Those are 4 minutes well spent.
9) Hwy 1 was beautiful, and the Model 3 makes the twisty curves hardly noticeable. EAP is not yet up to handling Hwy 1, but then who'd want to use EAP on Hwy 1 :-). Much of the route is without LTE (or even cell) coverage, so plan accordingly. Route guidance still seemed to work w/o cell coverage, although it was pretty insistent about taking us up 101. Had to get well past San Simeon before it relented and stayed on Hwy 1. Hard to tell if that insistence was due to duration optimization, or road closure/charger availability (we had plenty of range and the roads were open, but impossible to verify w/o coverage). It will be nice when the navigation app gets waypoints so all of this can be planned in advance, even if you decide to take the longer route.
10) Supercharging: we only had 1 situation where there was no chargers available: in Fountain Valley. There were a bunch of Tesla's waiting, and it seemed to be a free-for-all, so since we had enough charge to get to a much less busy charger along our route, we opted to do that. Another time, I got the last station in Monterey, but there the waiting cars lined up, and were all in spots within about 5 minutes.
11) I got a software update (32.5) during the trip, and since the past several updates went without a hitch, I allowed it to install. No issues, but no noticeable differences (vs 32.3) ...
12) In all cases, my charging was done before my wife was ready to stop shopping :-).
Being able to do long distance driving was a selling point to the Tesla, and in this regard, did not disappoint.