I thought the point of the NYT article was to review the Supercharger network, not the car itself. Plugging into a regular charger unnecessarily (and it would have seemed unnecessary at the time) would defeat the point of the article.

If you're being at all conservative, and your estimated range is that close to the wire, it doesn't seem unnecessary, especially when the standard usage pattern with EVs is to plug them in every night. The Model S seems to be doing a much better job of estimating its battery life than any laptop I've ever owned.