Alexa has the ability to place calls. Since Google has pulled 3rd Party support for Chat/Voice/Hangouts why not look into Alexa integration with PIAF. Not only could it do some cool stuff like IVRs, but you could get a trunk for free domestic calling too. It can call any PSTN number in the USA or Canada. I know of one Alexa SIP implementation (https://siplexa.com/) which is great, and free. But, because it is not an "officially recognized device", it doesn't have the ability to make calls. Admittedly, I have never tried it with an account that I have an official Alexa device linked to. Anyway, food for thought.