I just looked at the forecast - looks really nasty for Sunday and Monday. There is a nice Hostel near Coast Camp. If I were you I would plan on spending Sunday night at the Hostel.

Be aware that in heavy rains the coastal cliffs are not safe - be sure to stay away from the cilffs and do not hike on the coast directly under a cliff. Glen Camp is the most sheltered camp. I would definitely avoid Wildcat on Sunday night! Sky camp has some timber shelter but it is up quite high - likely to be very windy. Coast camp is half an hour from the Hostel so I suppose you could bail out there if needed.