It's quite likely that you'd be able to connect a Varia to your Garmin watch if it's a reasonably recent model. Then you could get radar alerts as vibrations on the watch.
Saw 600 in Shanghai a few years ago. It was horrific. Fortunately the Chinese government has made quite a bit of progress in improving air quality in the last decade so such terrible pollution isn't nearly as common today as it used to be.
I'm in Shanghai. I mostly get around by bike, but if I need to go somewhere far or the weather is bad or I'm going with the family, I take the Metro. I don't own a car and haven't driven in ages.
Battery life on my Varia is pretty decent, plus it can be run with external power if you're on a really long ride and you need extra run time.