Up to you really, do what you feel comfortable with. I've always been happy to let my ICE vehicle get way down before refueling, I don't know if it's from having a good understanding of fuel management with my aviation background or what.
My first ever road trip in a Tesla I did let it get down to 5% for one of the stops, which was slightly anxiety inducing, but after that it didn't really phase me, as long as I know I have enough to divert to another charger or two, I'm good.
My first week with the new Tesla, I let it get down to around 10% before I recharged it. I did do some opportune small charges through the week based on when power prices were good or I just had excess solar with low feed in rates.
Just do what works for you, you'll get more comfortable with it over time. Just make sure you have options, especially on a road trip. Tesla SC's are very reliable but always have that plan B in your mind when deciding how far to push it.
I used to be a glider pilot.
Range anxiety sounds a lot like the anxiety that glider pilots endure when flying cross-country without an engine. You always have to have a plan in the back of your mind to deal with the fact that the 'lift' can go away at any time.
If you are an experienced pilot, and have a high degree of trust in the fact that 'the next thermal is out there somewhere' and that you'll be able to find it and use it, then your press on.
But if you're crossing badlands, or the weather is deteriorating, you always want to get and stay as high as you can (like having a fully-charged battery), which gives you the greatest possible range before landing. If you don't find another thermal, you ARE landing.
The best place to land is at an airfield - because then you have the option of calling in a tug-plane and getting towed out. Expensive, but fast. Or you call some mates to bring the trailer, you take off the wings, stow the bird and drive back to base. This is like planning to stop by a supercharger, I guess.
I've landed a couple of times in paddocks out west. Very safe if you know what to look for and if you make the decision to land early enough to give plenty of time to plan for the landing, inspect the paddock, make a clean circuit, remember to put the wheel down. Ideally, you'll be near the farm house (phone, cold drink, etc.).
A good glider pilot will always try to have a few options on the boil at any time... and I guess it's the same for charging stations.
Photo is many moons ago: bringing the (club-owned) baby back home after cross-country flying camp.
And this one is even earlier: me heading off for a cross-country flight from Forbes.
