I can understand their worry, but the thing is it will take a lot more than the temp at 32 deg. to freeze anything. it would take a full week at below 30 deg. to freeze anything in the ground. now the spigots, well they will freeze at 30 deg. but not at 35! we were out one year in mid Oct and the temps dipped into the mid 20`s at night. the only thing that froze (slushed up) was the spigot and a few minutes with the hands around the pipe unfroze it. even the hose that was laying on the ground didn`t freeze (ground is still warm).
Personally they got too worried!
I wouldn`t have gotten upset over it, I would`ve just filled the water tank and went on with everything.