They're already producing 10nm DRAM with their current nodes, and they're working on producing 3d DRAM which may make node size somewhat moot.

Not 10nm, they are producing with 18.5nm and 17nm now, which technically already is in breach of US restrictions, the US government can blacklist them if they feel like it.

3D DRAM is no magic, it will only give them maybe 2 generations' breathing room if they got the required etching equipment figured out. But others will be doing 3D DRAM with EUV by then.