Interestingly, whilst Wikipedia does say that, the language in RFC 1591 (Domain Name System Structure and Delegation) only says:
There are a set of what are called “top-level domain names” (TLDs). These are the generic TLDs (EDU, COM, NET, ORG, GOV, MIL, and INT), and the two letter country codes from ISO-3166.
Likewise, in ICANN’s PRINCIPLES FOR THE DELEGATION AND ADMINISTRATION OF COUNTRY CODE TOP LEVEL DOMAINS, they say:
‘Country code top level domain’ or ‘ccTLD’ means a domain in the top level of the global domain name system assigned according to the two-letter codes in the ISO 3166-1 standard
In neither case do they actually limit two letter TLDs to being country codes, they only state that all country codes in ISO 3166-1 are ccTLDs. In the RFC, the author does suggest it is unlikely that any other TLDs will be assigned, but this has obviously been superseded with the advent of gTLDs. Thus I still consider it likely that the .io TLD will simply transition to being a commercial one, rather than a country one.
Having said all that, it’s entirely possible I’ve missed some more recent rule that tightens this up and only allows two letter domains from ISO 3166-1. If I have I’d be glad of a pointer to it.
That’s the traveling bit sorted, but you suggested living there, and there are many more problems to overcome to achieve that.
As a previous commenter said, within the EU it’s doable, but you’re going to run into visa related issues trying to immigrate to most other countries. Some, perhaps most, of those can be overcome by throwing money at the problem, but others are more permanent. Even once you have a visa there are often limits on what you can do and where you can work until you get the equivalent of a green card, which can take years.
Then there are the logistics of living in your adopted country. I’ve known enough immigrants to know it’s possible, but also how much effort it takes, especially if you’re moving as a family. There may be a new language to learn, there will certainly be a new culture, and whilst you can probably get by for a while, long term you need to learn it and integrate into it, or permanently be the outsider.
Then you have the upheaval of your life. Leaving your family and friends behind, and walking away from all the little things you know that make living where you do easier. These you face moving even a comparatively short distance, but they’re magnified going overseas.
Of course it’s possible, but it’s nowhere near as simple as you suggest.