1st year I moved in didn't know about this - after 3 days below freezing mine froze - not too long - not too bad - nothing burst - left the tap open & the water on - about an hour later - it unlocked.
Have next door neighbor that lives in Norfolk. The house here is a "weekend house". Belonged to the wife's grandmother. They don't come too often in the winter. Well we got our typical winter weather in February (only real cold month) & it stayed below freezing for 2 or 3 weeks.
They weren't there for the whole month. Neighbor on the other side of him noticed water coming out of his back door.
Nine pipes had burst bringing down ceilings & walls (old house plaster walls & ceilings). Whole place had to be gutted.
Similar situation on the other side of me. Guy lives in Virginia Beach. Works for the Navy. Lost two of them.
I'd let 'em drip.