While slow travelling, our plan is to keep our Schwab checking and brokerage accounts thanks in part to the free ATM withdrawals. I also plan to keep a Chase Sapphire Card (likely Reserve) as my main credit card.
Not sure whether we'll be using my brother's address as my mailing address or using a mail scanning service; I guess it'll come down to whether or not he's willing to put up with the hassle.
Haven't researched cell phone plans as much yet. We both have T-Mobile in the US, which has been great for overseas travel with no charges on data in other countries, but I've read that they cut you off if you spend too much time abroad. Would be interested to hear others' thoughts on that issue, or general thoughts on good phone plans for slow travel.
We're eventually planning to settle in my wife's home country (after returning to the US for a short while) and I imagine that will require another game plan, but we'll cross that bridge when we come to it.
@aspiringnomad, +1 to your plan to use your Schwab Debit card to access cash at ATMs. We're doing the same, and it's been working great. My wife and I also each opened Chase Sapphire Reserve and Chase Sapphire Preffered cards before we left the US. After spending $4K on each of the cards, we got about 350K points total, which we've recently started using to buy plane tickets. Before the yearly fees came due on the cards, we cancelled all of them except one CSR, so we could keep getting 3X points on travel/dining expenses and also to keep our Priority Pass, which gives our whole family free access to awesome lounges at airports all over the world.
Cell phones: Before we started traveling in December, 2016, both my wife and I opened Google Project Fi accounts. At first, we really liked Project Fi, but after a bad experience we had with them, I really wouldn't recommend them to anybody who is traveling outside the US for any extended period of time. The problem we had with Project Fi was that the phone they required we buy in order to use their service, the Nexus 5X, died after only 11 months. Since the phone quit working within the one year warranty period, I thought there should be no problem getting it replaced. Since I had purchased the phone directly through Google Project Fi, I contacted their customer service and ended up wasting hours going round and round with them on the phone from our hotel room in rural Cambodia where we were traveling at the time.
At first, they were like, "Sure no problem. We'll send you another phone." But, then, when they found out we were in Cambodia, they were like, "Uh, no. We're not going to mail you a replacement phone there." They said they would mail my phone to my brother's address in the US. That sounded okay, as my brother said he wouldn't mind overnighting the phone to us via Fedex. But, then Google Fi told me they needed to send me a link that I had to click on to verify that I was returning my phone under warranty and to print out a shipping label to use when I mailed my old phone back to them. The only problem was, when I tried to click on the link Google Fi sent me I kept getting an error message.
Once again, I had to use my wife's phone to call Google Fi customer service, spending hours more on the phone, until finally somebody realized that the reason I was getting error messages when I clicked on Google Fi's link was because I wasn't in the US. Apparently, you can't really do anything with your Project Fi account or phone unless you are physically in the US. The Google Fi people were like, "Oh, well then, no problem. When you get back from your trip, just let us know and we'll send you another link and you can take care of it then. When will you be back in the US?" I told them I had no idea when I'd be back in the US. Silence. Anyway, finally I just gave up on getting warranty service on my phone from Google Fi. It just didn't seem worth it to spend so much time arguing with them on the phone.
A brand new Huawei Android phone was only a couple of hundred bucks at an electronics shop in Kuala Lumpur, and I like it a lot better than my old Nexus. Pretty much all over the world, except for the US, pre paid phone/text/data service is super cheap. As soon as we got to New Zealand I bought a SIM card and monthly phone plan with 1.5Gb of data for like NZ$20/month, which is only US$14. For the past week, we've been back in Kuala Lumpur. Apparently after 3+ months my old Malaysian SIM card had expired, so I had to buy a new one at the airport, but the new SIM card, X minutes of calling, X texts, and plenty of data to last me for a week in Malaysia only cost me MYR18.50, which is US$4.50.
Hope you guys enjoy traveling. :)