I don't believe one or two nights at 28 outside will do any damage to your p traps inside. I wouldn't make a special trip this weekend but I would do it before the full winter sets in with prolonged freezing weather.
The water would have to freeze solid to crack the pipe. A cracked p trap would drain the water in the trap onto whatever is under it. The sink traps should be an easy & inexpensive repair if something did happen, cheaper that driving 200 miles round trip & the time. But I don't think that would happen.
I would roll the dice.
