By chance, Licwid sent me a link to some waterproof socks yesterday and I had my solution. I already owned a pair of those and if I paired them with my trusty sandals, I had an unconventional, way to get to GZ and keep my feet dry. I don't know how you'll fare, but I suggest a boat, hip waders, or coming in the Winter.
Parking coordinates placed North of the cache and this is the best side. The cache is NOT on the road. Do not go there.