Actually, we don't disagree. It is just that when someone is not certain of what to do it is better to suggest him charge too long rather than too short.I respectfully disagree with some of WarpedOne's answers
When he has more experiences he will not have to ask, he will be able to predict how much "over-range" is enough of a cushion in his particular circumstances to warrant a go.
What works in the summer may not in the winter.
What works in cold may not work in hot weather with strong opposing winds.
What works in slow-speed traffic may not work in empty road and hurry.
What worked with 19" all-years may not work with new 22" sport summer tires.
What works when alone may not work when loaded with 5 ppl.
What worked last week may not work anymore after you hit a pot-hole and damage the suspension.
What is certain is don't mind the battery wear when you need 100+ mile range. It is there for you to use it.
100+ miles is easily more than two hour drive - lots of unexpected things can happen in that time but one thing is certain - it will REALLY suck if you ran out of charge.