Is it the case that if the servers are down/unreachable the tractor will refuse to start, or simply that the automation features will fail? In the latter case you have to go back to the old system of having a human behind the wheel directing the machine. Most of the time that is the farmer, his family, and some hired help on really big farms. Food prices go up due to increased wages, but it's not a catastrophic food shortage as grain rots in the fields.

If it's the former then John Deere has set itself up for some massive liabilities if their servers crap out for extended periods during critical planting/harvest windows.