Depends on how much of a risk taker you are. If you look at the historical temps at this site (thanks to Rose for posting long ago), you will see it is not at all unusual for temps to go slightly below freezing at night in late October.
http://www.erh.noaa.gov/er/box/dailystns.shtml
But, it usually isn't a hard freeze. It may not be long enough or hard enough to create a concern. But as stated, it depends on the whims of Mother Nature. It could be.
If I were you I would base the decision on how quickly and easily you could get to the house if an unusually long, cold, night was predicted. Or whether you were willing to open a faucet enough to keep things moving enough to prevent a freeze at this time of year.