In general the reason for migration as a lifestyle instead of being sedetary is because they can't stay in place. The "jet-set" or even "RV lifestyle" are deep anomalies of those who don't have that concern.

If there was a year round harvest they wouldn't be migrant workers. It brings to mind a "silly stopgap" solution mix of paying people in low wage countries to operate farming drones to subsitute for the AI in spite of the cost of building the body being higher and the infastructure and tools required to control a bot not corresponding with migrant farm worker origins.