This thermostat has a 12V power supply which you can get from your old desktop, wi-fi routers and plenty of electronics. Even the remote key of your car operates on 12V.
Second thing you need is to adjust the temperature probe to the fermentor.
Third thing you need to do is to make sure that thermostat cut-off switch is attached to your cooling pump (if you are using an icebath chiller) or to your refrigerator/peltier if you are using active cooling.
Fourthly test and dry run your setup before leaving for your office.