I do believe that the Russian economy can survive at the moment, even if the sanctions are getting worse. At the beginning of the Ukraine Russia war it seemed very bad for Russia with all the sanctions, the biggest one removing Russia from swift system. The concern were that Russia is going to default on its foreign currency debt. This didn't happen luckily. American banks still keep open channels with Russia and coupon payments have been made. So Russia is not completely isolated and the debt prices recovered considerably. As for all dealings in rubble, Putin can just print more of them.
The main export for Russia is Oil and Gas, while some countries and companies said they are not going to make new contracts with Russia for future supply, the old contracts are still valid and being paid. Many countries in the European Union made it clear they are not going to stop relying on Russian imports. It's one thing to try and hurt Russia, but you can destroy your own economy because of it. Fuel prices are through the roof in Europe, inflation is rising. I think the West will keep trading with Putin and stabilise the Russian economy.