It really takes little time to winterize and cost little. And little time to put it back in service. My wife or I do it several times a winter. We drain the tankes and blow the water lines, add some antifreeze to the holding tanks several times a year or do the whole job.
I once held off and after replacing some lines both water and drain after they thawed while parked at Disney World I decided the heck with it and just made up a check off list to put it into service and take it out. Lots less work than redoing the plumbing.
We feel the only way to do the job is to follow a check off list so you never forget any thing. However many of out friends just keep their rigs hooked up and heat ect on all winter saving them the few min of winterizing. I always seem to find other things to do with the money I save winterizing.