Driving the West Coast in October
We've already committed to visiting NZ in early October, before we realized that October is the wettest month and there can be torrential downpours affecting the coast road. We plan to leave Greymouth around 2pm, and driving to Franz Joseph, a 2.5 hour journey (4 hours with stops, etc). The next day, we plan to drive from FJ to Wanaka - a 4.5 hour journey which we expect to take 8 hours with stops, etc.
I'm totally ready to pull over and wait if the rain is bad, but I've read that the storms in October can be long lasting. Could the storms be so bad as to prevent us making the journey? Do people cancel hotel reservations during this period, due to weather? Are the storms worst during the day, easing off at night? I'm just trying to get a sense of what to expect, and what to plan for.
I'm already familiar with the NZ weather page - https://www.metservice.com/warnings/home and I've loaded it on my phone.
I've read that cell service is pretty limited on this road. Do the police patrol this road pretty frequently, and/or tow trucks? (I'm just thinking about flat tyres, etc).