Not true : This would not be an all-time record low for that station since there was -89°F/-67.2°C on 18 March 2011, which is the real all-time record at that station.
— Etienne Kapikian (@EKMeteo) January 4, 2020
-86.8°F/-66.0°C would only be a January monthly record at the station (if valid ; data is still preliminary).