I use an upright as a kegerator. Mine is an older model and only had one thermostat for the freezer and a manual damper to control the fridge temperature. I removed the thermostat and wired my STC-1000 in place of the factory thermostat. Keeping the damper closed allows the freezer to stay quite cold while maintaining the fridge temp. I keep hops, dry yeast, ice packs, and some bottles in the freezer.
Look at the bottom and back of your fridge for a packet that has the wiring schematic. That will help you decide the path to take.