iolinux333 is right... Can't set up Calling without the contact list. If you try and don't allow contacts on a Smart Phone, it still won't allow you to use it... I think it' a Mole to take everyone's Contact list and sell it to marketing firms and researchers.
I imagine you could use ANYONE's Smart phone to set it up, and make sure you're number is always on that phone's contact list, and The Alexa stuff could be set up with that person's contact list and will likely work fine unless they remove the listing for you... or lose the phone or replace it or whatever scenario comes up. I have 3 spare smart phones we use as iPods for music and smart house features... Probably should have set my Echos up with one of those instead of my daily driver phone...