Thanks for the additional tips. Will investigate getting the kit installed. In my defense, our unit's manual's instructions on winterizing specifically say to do so by putting the antifreeze in the water tank. We were trying to avoid that by doing as was suggested on several posts (I spent about 3 hours reading the board before posting in the first place). Unfortunately, we did not know our unit was not set up to avoid putting the antifreeze in the tank. Now that I know we can have something installed, we'll do just that.
In the meantime, we do know how to clean out and sanitize our water tank, so that won't be a problem in the spring.
Thanks, everyone, again for always being helpful in our most boneheaded times of need!