Are you referring to yourself in the third person, or someone you know? 800 feet is tight but doable especially on a cfi ride. My oral was nine hours long with a one hour lunch break so I'm glad yours/theirs was only five and half. Weather is a part of the job and the weather didn't seem unsafe to me, but ultimately it is the PIC decision and I won't begrudge them that.
It does seem odd to reschedule three or four times.