If you're winterizing and the gas is off, I presume you mean it's stuck on in 110v. mode, Les. You could unplug the coach of course, but flipping off the fridge in the main breaker box or unplugging the fridge from its outlet in the back are options if the rig needs to stay on 110v. to keep the batteries up.
Of course that doesn't resolve the cause, such as a bad switch or circuit board. That's likely to still be there next spring. Commonly the on/off circuit, controls, and any digital readout is run on 12 volt while the electric element side of the boiler heater is 110v. Some older units had a third heater option, 12v., but my hunch is that yours doesn't. Regardless, if you can locate and pull the 12v. fuse for the control board, that should shut things down. Unfortunately mine is a much different coach and Dometic fridge, with breakers and fuses all in one cabinet, so I can't tell you where your breakers and fuses are.
Joel