He should have sat down and done some math before doing that article. Either his "cabin" has crap for insulation, he can't measure a cord or that stove system is horribly inefficient.
He says it's colder but the cabin is smaller and better insulated, so lets say they are about equal as far as heat load.
If it costs him $1000 a year in nat gas to heat his house in NJ, that would be 72,857,142 BTUs based on $1.40 per CCF (the low end of New Jersery avg cost)
Let's say he is burning decent hardwood, which is what Maine has, avg 25,000,000BTU/cord.
6 cords is 150,000,000 BTUs, or over 2x the BTUs of heating with nat gas.
He would need ~3 cords to make same BTU levels, or a cost to him of $675, a savings of $325 a year.