JAXA DATA Global Extent as at 23 Jan
With, on average, just 3 weeks and 9 % (0.8 million) of extent loss to go, Jan 23 extent today is now lower than all previous years' minima except 2017. Jan 23 2017 extent was just 2.370 km2 less than 2018.
If, always a very big if, extent reduction is average, the 2017 extent minimum would be nearly 400,000 km2 less than the 2017 record low minimum.