This is part 2 of searching for an SMS notification solution. See SMS Garge Door Status - Attempt #1 of this project log for part 1.
At one time there were solutions for using an RPi to text through Google Voice, but no more. Unfortunately, the wind-down of Google Voice includes them having already turned off the ability for generic third-party access like that. (Thanks again Microsoft for the roll you played Google's decision to shut Voice down!)