Talk of Gazprom leaving Ukraine is premature. Too big a gamble even for Putin. The notion that someone could step in and take GZP's place is not unsubtaniated.
http://bulgariaanalytica.org/en/2019/01/31/prav-iznos-na-ukrainski-gaz/
A deal for a new 10-year transit contract in the making. Both sides - Ukrtrasngaz and Gazexport insist talks happen between experts - no politicians.