Russia is cash rich and in the black, so they can run for a while.
Meanwhile, China will be interested in extra oil, and just loves to not do what we ask (a boycott), and some one's economy must go without oil right away, who's it going to be, Europe or the US?
Their cash position is contracting. Western capitalists are making for the door and cash inflows from investment are way down. The big money guys are starting to see that the Russians can't be trusted to keep their mitts of foreign owned assets. Cutting off oil to the west will play hell in the short term. Medium term and beyond? They can't eat oil. And wars are expensive.