1/2 OT: The Apple Watch does not work with captive portals either. And since 4G does not work abroad, I can use my Apple Watch without my iPhone nearby only in my home country.
What do you mean? I can roam 4g just fine.
(For example: I bought my Watch in the U.S. While on vacation to Ireland, my iPhone connected to Vodafone IE without a problem. But my Watch showed "no cellular service" if it was out of range of my iPhone and a wifi network.)
I asked my Norwegian carrier about this, and they said yes, but linked the page where Apple says roaming is not supported...