If you have an old Wii connected to watch Netflix you will have to find an alternative as Netflix stops support on 31 January 2019.
Netflix already sends emails to his clients with a relevant announcement, to them warns that Nintendo will launch after 31 January 2019, a "suspend" of Netflix as well as other video streaming services for the Wii. Termination will come as the Wii Shop closes and the 2006 dating console will be useful only to play offline games.
Netflix does not offer any alternatives other than for users to purchase newer hardware. In particular, he states: "We hope you enjoy an even better Netflix experience on a supported device soon."