Allow me to suggest that you may be overthinking this just a wee bit.

Haha! This post was after removing 80% of content. I honestly am really enjoying the planning process - I'd not have been as verbose otherwise. :P But I totally get where you're coming from - I suppose, I'd rather sort as much of this out in advance and leave the adventure of cultural immersion, making sense of foreign language labels on grocery items, and so forth for when I arrive. :D

Schwab is a good choice for places that deal in cash, but I'd also look at offerings from Wise, Revolut, etc., for backup and better fx rates. Redundancy on the road is a good thing.

Yup - I was thinking the 2 checking accounts met the redundancy goal - are you suggesting having >2? And thanks; I'll start looking into Wise and Revolut right now (I'm unfamiliar with them). I'm not sure how they can beat Schwab's 0% fx rate (and no ATM fees) though?

Banks don't like to deal with you not being in the States...

Bummer - I was hoping that had improved in the past decade - thanks for letting me know. And yes, I'd be routing via VPN for greater control/security when engaging financial accounts regardless. :)

Discover. I've not seen Discover being accepted outside North America except for hotels and airlines that cater to US clients (i.e. expensive). I would suggest not prioritizing points until you work out how/who/where your spending goes and then figure out what is possible.

Agreed. I did a lot of reading and saw that Visa > MasterCard > Discover > AMEX, when it comes to international penetration (i.e. likelihood of payment being accepted). Thus, Discover is my backup's backup card. And yes, I'm not prioritizing points at all. I think dealing with that approach is too much hassle, plus my spending behaviors may change - hence the focus on cashback rates being applied equally to all charges (i.e. non-categorical spending). The non-categorical approach also removes the headaches of wondering whether a particular shop/restaurant/other is categorically registered - for instance, I've often visited brick and mortar sit-down restaurants (in the USA) that weren't recognized as "restaurants", thus didn't get rewards in the past. It's just not worth the headache, imho.

I would also suggest using an Amex charge (not credit) card as your primary card with Visa/MC as a backup...

Given my response above about AMEX being the least accepted of the 4 payment providers, I'm surprised to read your suggestion here. Perhaps I am misinformed? Would love if you could elaborate further! Also, do you know the fraud risks of charge cards? I've only used Debit and Credit, and found the latter to be a lot more secure.

Apple Pay (and I assume Google/Samsung) are game-changers...

Awesome! I was hoping mobile pay apps had caught on internationally. Would you mind sharing where you have (or have not) had a good experience using these? I'm specifically interested in Apple Pay, FWIW.

Google voice (i.e. number forwarding) doesn't last long outside the US, ...

I had no idea about the 6 month limit, that's a super helpful insight, thanks! Unless the Skype number truly acts like a virtual number, in that people using PTSN (i.e. not using the Skype App) in the USA can call me on my virtual number, then this wouldn't work for me. With that said, I got the latest iPhone, which supports dual SIM (2 eSIM, else 1 nano-SIM + 1 eSIM), and set mine to eSIM, so as to maintain it and get a SIM in any country/city I visit while abroad, in case of just this scenario. It's not convenient switching between the SIMs, though I've figured out how to keep both simultaneously active, with it 'defaulting' to one particular, thus keeping international fees at a low, and always giving the impression of the same phone number to whomever calls. But, I'll admit, it's not as fluid as I'd like it to be - early days of dual sims, I suppose.

2FA - You don't manage it. Your bank tells you what the only option is.

Going to need you to elaborate here - I've got about a dozen banks, credit, and brokerage accounts. Every single one of them offers me a multitude of 2FA options (i.e. Physical Token, App Tokens, Voice Verification, SMS, Email) - I've never seen a financial entity NOT offer >1 options. However, none of my dozen accounts offer the same options, nor is there 1 universally accepted option across all of them (with the exception of SMS, but as raised, my concern is SMS may be a problem with virtual phone numbers)

VPN - This is a good idea...MiFi...

Aye! I manage my own routers (personal and, in the past, for my employers), so am totally down with this. Sounds like you've done some techie research here yourself already - any particular reason you chose the MiFi over competitors? I've not yet looked into figuring out my home network / extending of networking technical solutions yet. Would love to read more about your experiences and approaches here when traveling and needing to work.

FYI, from a tech perspective, this was all I planned to bring (for 2 people): 2-3 laptops, 2 smartphones, 2 wired/bluetooth headsets, 1 wired keyboard, 1 wired mouse, 1 laptop extendible monitor (example), and possibly 1 compact drive (for backing-up laptops, though Cloud Storage might be more sensible as a DN, thinking about it).

Insurance: Yes! If nothing else, this pandemic has demonstrated that the unexpected can happen. Staysure...

Thanks for the tip! I've yet to properly delve into all the insurance options out there; I'll start with looking at StaySure. :) I'd likely be wanting an ex-US global insurance, as opposed to country-specific insurance coverage. My rationale here is that, while I would be going to specific countries for 3-6 months at a time (depending on VISA rules; I've spent a lot of time reading into those and some are a nightmare, while others are a simpler [albeit annoying] border crossing or waiting of a few months to return requirement), I'd likely visit neighboring countries. For instance, when in Portugal, I'd likely take 2-3 weeks to visit a friend in neighboring Spain, as well as take the ferry there to/from Morocco.

TL;DR - I have too much time on my hands. Learn how to be bored and productive.

Haha - I love that you took as much time as you did to respond here. Even if not productive for you, it certainly was for me! Much obliged for your input; thank you!