At least bitcoin will be mostly unaffected since you can receive blocks via satellite [1] and if even one satellite connected node is inside Runet then you can at least keep up with the blockchain. Sending transactions can be done via sms [2]. The main problem would be mining in Russia, but if miners know about the shutdown in advance and it's economically feasible then they can get satellite internet to upload found blocks.
One person is enough. If one person inside Runet receives blocks from the wider internet (via satellite or other means), their client will automatically forward the blocks to all clients they are connected to, quickly spreading them accross Russia. And because Bitcoin follows the chain of blocks that took the most work to create, latency isn't an issue.
Mining (and making a profit while doing so) is more latency sensitive, but should be able to tollerate a satelite uplink. And again, one person having a satelite uplink is enough to give all Russian miners a chance.
Mining is mostly a game of getting cheap electricity, and it's hard to beat China (where infrastructure construction is often about creating jobs and projecting power instead of classic profitability).
It seems like electricity prices in Russia are similar to the US. The legal position of bitcoin seems to be worse in Russia though, so you would expect less mining than in the US, and a lot less than in China.
