You can port your phone number to a voip provider if you will be out of the country for a while. Use a sip phone app, and the "transport layer" sim that you happen to use will have nothing to do with the phone number that is intermingled with your identity.

This is way too much hassle even for me as a techie.

And something tells me short-code SMS receipt (which is what banks use for 2FA) is not going to work well anyway.

If you don't need it, you don't need it. But for the record:

a) Porting your number takes about as much effort as moving between mobile phone providers

b) Setting up a sip app on your phone is trivial (server, username, password) - I'm generally a fan of Acrobits Softphone

c) My voip provider has an sms <> email gateway, so my bank (and other sms based) mfa lands in my gmail inbox