Looking for Holtz That Moved to New Zealand

Kia ora koutou,

My name is Chanelle Holtz and I am looking to find my great grandfathers family. My grandfather is John Holtz, and his father, Herman Wilhelm Hans Holtz moved to New Zealand by himself from Stuttgart, Germany when he was just a young teen. I don't believe we have any records of his family and I would love to get any information anyone may have. Herman was born on 8 Jan 1883 in Germany and died in Kaikohe New Zealand in 1975.

Cheers!