Have you thought about being homeless? I don't mean sleeping in a box. I mean not having a residential or "physical" address? It's actually very difficult to do in our modern times. I learned this first hand when family members flooded out of Lyons, CO came to stay with us. My brother-in-law had to quit his job, since they lost their home. They couldn't get a health insurance quote until they had a physical address in the state of intended residency. Seriously, not even a QUOTE! (Their intention was to continue eastbound). Odin will be our home, but will be in relative constant motion (ie. staying less than a month in each place--faster than the postal service can forward mail), and we plan on anchoring out (ie. not paying for marina slips with a physical address). Here's what I've learned, and it's far from complete:
You cannot use a PO Box on your driver's license or many other government documents (I heard someone got "homeless" put on their driver's license, but I'm not going to try it). Did you know your car insurance rates are based on your mailing address? When my father-in-law stayed with us, we tried to change his mailing address. They wanted to know if he was "visiting" or had moved because it would change his rates. We also had this problem when we tried to update our mailing address while the house was on the market--even though it was the next county over. Some full-time cruisers have come back after an extended absence and had their car insurance company say they are now considered newly insured (This sounds a little off, but the word you should use instead of cancel is "suspend".) What if you want to rent a car out of the country? You will need a US driver's license & probably should have some form of insurance (you can carry limited coverage).
The word for living outside the country for extended amounts of time is "expatriate" or "expat" for short. Apparently, Social Security is the only entity that understands expats. A large number of social security checks are deposited overseas (with no way to track those that live abroad and still use their hometown bank).
If in 2016, we live on the boat full-time in the Caribbean, do we owe state taxes (house sold in 2015 and only income is from investments)? As far as I can tell, the IRS says yes, even if you don't meet the residency requirement of any state--which is 183 days in Missouri. Did you turn in your license plates, drivers license, voter registration and library card? Then you are still a resident. The state of your mailing address and health insurance may be referred to as your "domicile." The state of California is the worst. You are considered a resident and owe taxes until you prove you are a resident of another state. Your best bet is to establish residency in a state that doesn't collect state income taxes (but beware, they may hit you with "other" taxes like personal property tax of vehicle/boat registration).
(http://www.usexpattaxhelp.com/Expat-State-Tax-Return.php) or (http://www.taxesforexpats.com/articles/expat-tax-rules/state-taxes-expat-tax-return.html)
And the bank wants a "residence" address not a mailing address. If they get wind that you aren't living in the US, they can close your account. (http://www.wsj.com/articles/expats-left-frustrated-as-banks-cut-services-abroad-1410465182) or (http://www.reuters.com/article/2014/06/11/us-banks-expats-idUSKBN0EM16V20140611)
Most health insurance is only useable out of the state if you go to emergency room. NONE will work out of the country. But Obamacare requires it or you are penalized on your taxes (there is supposed to be a way to waive this is you prove you aren't a full-time resident).
So what do you do? Many use a family members address with some going as far as signing leases to prove their residency (what if you get a jury summons?) RV'ers are a great source of info (http://rvroadtrip.us/library/mail.php) ie. if you are moving on a regular basis, how do you renew your license plates and drivers license? There are states that are friendly to this lifestyle. Some cruisers & RV'ers use a mail forwarding service that will scan, forward or shred your mail. We may go this route next year (we'll be Missouri residents for 2015, at least). However, I've heard stories of mail forwarded outside the country never reaching it's destination.
Modern times allow us to go "almost" paperless, except for our Coast Guard registration which must be signed and returned (then we will need a copy of the new registration). I've spent the last year trying to stop the flow of mail, but I don't think it's quite possible yet (The IRS is still sending letters about Husband's deceased father's return from 2013.) I have an Aunt who keeps calling and asking for my mailing address after we move out of our house. I finally promised to send postcards, but I know she'll try to write back--and we'll be long gone.
Do you want to get a hold of us? There is internet access in most marinas. If not we will head into town in search of a library, coffee shop or bar that does. Don't panic if you don't hear from us for a few days. WE LIVE ON A BOAT :-)