This is just a general discussion and not specifically cycling related. I just discovered that in mainland China, Google doesn't work. So that means you can't access your gmail although other e-mails may work. Google maps will not show you any detailed streets so try to get, if there is any, a specific map app for China. Google the search engine doesn't work so check beforehand if Bing or download another search engine that's China-compatible.

Not even the osm Garmin maps in your GPS work in China. They did when I was at home but not when I landed at the Shanghai Airport, all the street details disappeared.

So another thing to check is if Strava works. I post here because Bike Forums is only a handful of websites I can still access. I went into Tripadvisor.com and posted a question but it just spun endlessly when I submitted. So that didnt work.

If you use repaid SIM from Hong Kong, or just doing roaming then you could get access to Google service also the map.