Frost won’t cause a hose or hose bib to freeze and break, it needs to be really cold, so you should be fine. We have turned our hoses on (I also live in zone 5 in the Hudson Valley).
Welcome! I’m Margaret Roach, a leading garden writer for 25 years—at ‘Martha Stewart Living,’ ‘Newsday,’ and in three books. I host a public-radio podcast; I also lecture, plus hold tours at my 2.3-acre Hudson Valley (NY) Zone 5B garden, and always say no to chemicals and yes to great plants.