I've been planning on a similar modification for my fridge for a year or so. Until now, I've been disconnecting the light/heater wire at the circuit board but I discovered that that's a dangerous thing to do when the fridge has AC power because the nearby fuse with exposed contacts is apparently for the 110V heater. (Please don't ask how I discovered this.)
Instead of installing bullet connectors, I'll probably mount a switch on the sloped panel of the light housing. This will make it easy to turn off the heater when boondocking.