sure you can do all that, but I think there is a much better way. Leave the reefer running and attach a compressor to the city water connection, just like you do to blow out the water lines.
Blow out all of the water lines by turning on the faucets and letting the water come out, just like you do for general winterizing.
LEAVE THE COMPRESSOR ATTACHED for 24 hours and leave the icemaker on. It will cycle on its own and eventually clear all of the water from the lines and icemaker.
CLOSE the pop up valve that goes to the reefer. Winterize all of the rest of the plumbing by ingesting RV antifreeze through the pump and running it out of all of the faucets,(remember that shower if you have one) but none will go to the icemaker since the valve is closed.