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.

[1] https://blockstream.com/satellite/

[2] https://twitter.com/SamouraiWallet/status/954271930365947904