Even the sanctions on trade will not cause much harm (as only 2 percent of Russia’s exports got to the U.S. and mostly includes petroleum products, and only 5 percent of total imports from U.S., including vehicles, agricultural products, chemical products and civilian aircrafts, etc). They can always procure them from other countries.
Russia can survive by forging a close alliance with China. They are not allies the way the U.S. and European Union are, mainly because Russia expects China to have a go at Russia’s Far East at some stage. However, tactical needs for survival can trump the strategic concerns. That can result in close and truly cooperative alliance of China, Russia, Kazakhstan, perhaps Mongolia, some others, with China building high-speed railways all the way to Sevastopol.