can someone confirm - this - when in China, can I VPN back to my employer's VPN here in the US - they are a fortune 500 company - thanks

Unless your company has set up some kind of special obfuscation to hide the connection from the GFW, then it will most likely not work. If it doesn't, there are other solutions you can use if you must connect to it. Such as tunneling openvpn over shadowsocks or tunelling it though another vpn on a router. Contact me through the Tips for China website if you need further info.

If you're not travelling to China for business purposes, I would check with your IT department to see if they even allow that. I worked for a major US company and we had a list of countries where we were not allowed to use company devices due to fears of government surveillance and China was on that list.

do you set openvpn to port 443 or a higher number

It won't make much difference. It will get blocked very quickly regardless of the port number if you set up your own OpenVPN server without obfuscation. Check your email, I sent you some info.

Enterprise-style VPNs (like Cisco AnyConnect) have, IME, been exempt from GFW tampering. If your company uses an open source VPN or standard protocol like OpenVPN or straight IPsec, it's unlikely to work.

I am also going to China What VPN is Working in China?

All of these ones are still working well for me.

If you want reliability and without much drama and hassle, go with Express VPN. I've been using them for years and never a problem. My friends that has all kinds of VPNs, have all been disconnected (some of them restored) from time to time. Never for Express VPN.

strangely enough, my vpn back to my company and even back to my home worked without issue everywhere in China but both are enterprise-type vpn like anyconnect. Whatsapp and google don't work

The VPN situation in China is constantly changing due to regulations and crackdowns. What that means is that most VPNs will not work properly if they do not put resources into overcoming those difficulties.
As I know, only a handful of VPN providers are dedicated to serving the China market and those are the VPNs you should use.

You can find reviews and speed tests of those VPNs here: Jump the Great Firewall

Not necessarily VPN related, but a friend just returned from China and was roaming with his Canadian cell phone with Canadian SIM and everything was still blocked. In the past, most people reported being able to bypass the Great Firewall when roaming, because traffic is routed back to your home country first.

I believe there was another recent post on FT where another FTer reported not being able to bypass the firewall when roaming with a Japanese SIM. Does anyone else have any recent experience?

Google worked fine a week and a half ago on a T-mobile sim.

China Mobile HK SIM and Thai TrueMove SIM both still bypass the firewall as of today.

I know people don't want to discuss publicly sometimes, but I use PIA which I know does not work currently, I'll be PVG for a few days and am looking to use a VPN. FWIW I am using project fi so I assume that will connect to a local telecom while I'm there.