I am going to buy either a Move or a Five as my first Sonos speaker. but eventually plan on having several.  

It appears that both will allow me to set up my Dot or Mini with my Spotify account so that I can just say to the Dot or Mini play x and the music will come from my Sonos speaker (i.e., the Sonos will be my default speaker). Am I correct in this?

I also would like the Dot or Mini to respond through my Sonos speaker for all responses.  For example, if I ask what the temperature is, it would respond through the Sonos speaker.  It appears neither the Dot nor the Mini will do that, but it is hard to be sure from reading/viewing reviews.  Will all responses for the Dot or Mini be able to come from the Sonos speaker?

Given those criteria which would do what I want, the Dot or the Mini?  Am I correct in assuming that both the Move and the Five would work the same via WiFi?