The Environmental Protection Agency rates the present i3 as having 81 miles of range, meaning this tweaked version would be a 50-percent improvement if that range number applies to the US market (it's likely the more lenient European number, since Autocar is a UK publication). BMW said the update takes advantage of gains in battery efficiency over the past two years. The i3 with the range extending engine would also get the update, and current owners will reportedly (and surprisingly) be able to purchase the revised powertrain for retrofitting.
The Autocar report appears to back up a recent article in German newspaper Die Zeit in which BMW CEO Harald Krüger said the the i3 will get more range next year, and "Another technology leap is going to come in three or four years." The i3 was designed for to make these kinds of upgrades easy to manage. We wait to find out when it will be available, whether it will increase the price of a new car, and how much it will cost current owners to retrofit.