The trick to minimizing time waiting to charge on a road trip is NOT arriving at a each SuperCharger with a low SOC.
The trick is to not spend time waiting for charge that you don't need to reach the next SuperCharger (+ a small buffer)
Let's say your 1st SuperCharger is 150 miles away, and the 2nd SuperCharger is 120 miles past the first, and you like a 10 mile buffer.
If you leave home with 220 miles of charge, you arrive at the 1st SuperCharger with 70 miles of charge remaining, so you have to spend time charging from 70 to 130 for the 2nd leg.
If you leave home with 160 miles of charge, you arrive at the 1st SuperCharger with 10 miles of range, so you need to charge from 10 to 130 for the 2nd leg. Think of it as the time to charge from 10 to 70 followed by the time to charge from 70 to 130.
The time to charge from 10 to 70 is shorter than the time to charge from 70 to 130 because of the lower starting SOC, even though in both cases you're adding 60 miles of charge.
You arrived at the supercharger with less charge, so you have to spend more time charging because you need more charge to reach your target SOC (130)
Now consider the charging before you left home. If you did it while you were having dinner, packing, and sleeping the time to charge from 160 to 220 was not wasted because you weren't just waiting.
However, if you did it at a SuperCharger and waiting, the time to charge from 160 to 220 would be significantly longer than the time spent charging the next day at the 1st SuperCharger charging from 10 to 70. At least double, maybe quite a bit more. It's still the same 60 miles of range, but it is much more expensive in terms of time.
Moral of the story: If you're waiting while charging, only charge as much as you need to get to your next stop (+ a small buffer). If you aren't waiting, keep on charging!
Of course we should be considerate of other travelling Tesla owners, so don't hog the SuperCharger if it is crowded and you have enough charge for your next leg. Don't make someone else wait for a charge you don't really need.