I am keeping one of my T-Mo prepaid line, $30/mo with unlimited data ... really, it's 5GB of 4G LTE data/ excess is throttled - and 100 air-time minutes plus SMS - on an unlocked Nexus device, tethering not blocked (use it when out of faster/stronger/better WiFi signal range) - use it to forward calls to Hangouts but do make those occasional domestic (USA) cellular calls but stay within the allowance, mostly.
Now, if Project Fi would price match it
