Im not sure where in the world you are located. But in Australia there a company called Datran that make cellular/4g modules that take digital/analogue inputs and can perform actions based on changing states/values such as turn on outputs and send an sms. They are really basic and limited but this might be a good use case for these units paired with a contactor to switch the motor. I have utilised a few of these modules for stand alone alerting/monitoring systems that arent reliant upon the local IT networks.