Spark have the 3G/eSim version of the Samsung Gear S3 https://www.spark.co.nz/shop/mobile/accessories/samsung-gear-s3-frontier---black.html

I saw one on Kickstarter yesterday.

Having Google Maps would great. I want turn-by-turn directions for bike routes. Sad the Gear S3 doesn't have that :(

Maybe wait for the LTE version of the apple watch to be released in NZ? Otherwise you could get an iphone SE which is small, to use with the apple watch. Maybe even mounting a phone on the bike?

Already have. But I want a more seamless transition from 'off' to 'on' the bike and versa visa. And I don't want a phone with me everywhere, it tempts me. And I want to take a breather from the world. A smartwatch would be a nice middle ground, because it is limiting.