u/AsherClarke

I'm thinking of porting my USA number to Tello prior to moving to Madrid, Spain.

I live in L.A. and I will be living abroad for a few years. I'll need my USA number for two-factor authentication (2FA) for banks, etc.

Questions:

1. How is coverage in L.A. and California? Does it work well in other major US Cities? How good/poor is the coverage and data? (I currently use AT&T, so this will be my first time using TMobile and a MVNA.)
2. I've read that it's vital to activate, port and then enable wifi-calling prior to leaving the USA, so I plan to do this all about 10 days prior to moving.
3. How well does Tello work in Spain? I know there is a roaming option, but I've read that it's spotty at best, so receiving the texts and calls over Wi-Fi is going to be the best bet while in Spain? 
4. For the Wi-Fi scenario, what happens if you're off Wi-Fi? Will the texts or voice messages just queue until you reach Wi-Fi?
5. I'll be using dual eSIMs in an iPhone 16 Pro Max. So can my Spanish data plan act as the provider to enable the Call/Text over Wi-Fi, or is it just actual Wi-Fi only that activates the Wi-Fi calling?

I'll probably use DIGI for my Madrid eSIM.

Thanks for your advice.