See my take on this, I think (unless you are using your phone excessively or never return to the US at all) you should be fine with Project Fi at least.
Apart from that try getting a bank account which provides you with a special extra factor (Estonian banks call it a “pin calculator”) that lets you access your account regardless of being able to receive SMSes. I don’t know which (or if even) US banks have this, but you should do some research, maybe even your own bank has something like this, you just never needed it.
That said, @levelsio is completely right in that there isn’t any good digital solution, receiving sms-es on virtual numbers and the likes is always a hit or miss, no matter the provider, don’t risk it.
A propos, don’t risk it, I can very much recommend having multiple bank accounts and multiple credit cards if you are going to start traveling. Not being able to access your money from abroad, thousands of miles away from a branch office is one of the worst things that could happen to you (it’s certainly one of my biggest fears), so it never hurts to have multiple options, maybe even some of the new fintech stuff like Revolut or Monese, besides having at least two credit cards and ideally two separate bank accounts/cards.
I once had some of my credit cards expire on me in Singapore, then one of the ATMs took one of my credit cards, in total I lost 3 cards in a few weeks on a long trip. I still had 2-3 cards/methods to get cash so it was fine but finally it paid out having stuffed my wallet with multiple credit/debit cards in the past few years.