When preparing your sailboat for winter storage in late fall, it is best to replace all halyards and control lines with messenger lines. Doing this will save your primary lines from UV and chafe during the winter, whether your mast is standing or in a rack in the boat yard.
Wash all lines with fresh water, dry them thoroughly and inspect them for brittle/flaky covers, excessive wear and chafe. Winter is a good time to correct any onboard issues causing damage to your lines. Finally, consider replacing any damaged rope and store all lines in a dry location well-coiled. From your friends at Marlow.