According to the USNI article, the writer states the Russians accept as a given space based Satellite systems shall be rendered inoperative and have plans to use alternative means to replace the space based systems.
One such system was identified as being the "Sprut-N1".
They also have their own version of LORAN called "Chayka" that has three coverage zones in operation with a focus on the far North to facilitate their High Arctic Operations.
https://rntfnd.org/2019/03/01/report...s-inside-gnss/