PGrey, for many services using two factor auth, you can simply use the Microsoft authenticator. It is working fine with Google, Microsoft, Lastpass etc. as it is set on a standard. Here is more information on this, it is all the same
https://en.wikipedia.org/wiki/Google_Authenticator . This is generating a code for you every 30 seconds. The code is secure and can not be guessed. Even if somebody gets a hold of your credentials, he can not login and cause you all kind of problems.
For Microsoft, they are having a new authentificator app in beta, which is taking a lot of the pain out of it, as it simply pushes a notification to the phone, allowing you to verify with a single click. For this, you would need a connection (however WiFi would be fine). However, you can always just type the generated code.
You are all grown ups and can decide for yourself. However, reusing the same username / password on multiple sites and not using two factor auth, is really asking for desaster. Other people impersonating you, spending your money, crashing your credit ratings, ruining your reputation, you name it.
Sorry for being completely OT by now, but I am quite passionate about this. Criminals can cause you so much trouble and it is quite easy to not be easy prey.