Cryptocurrency nodes can be run on common ports such as 443, as well as over TOR/I2P. The addition of SSL support to mask node traffic would make them more expensive to detect (it would require DPI).
And I wouldn't worry too much about governments banning TOR. Freedom of speech and the enabling of citizens living under oppressive regimes to access information aside, if they banned it, how would the secret agents most governments have deployed in foreign countries, both allied and enemy, communicate with headquarters?

The only countries that can deploy somewhat effective "great firewalls" are the ones that have very large disparities between their population and the number of IPv4 addresses they have allocated, because such conditions force them to have large swaths of their internet using population operating behind a NAT.