We did a China trip two summers ago and didn't have any issues.
As others have said, I informed my credit card companies of our travel dates - many of the major CC issuers allow you to do that online now which makes it so much easier.
We used our CC for a few larger purchases (we were with Viking, but my wife and I stepped away from their tour to go to Shanghai
Disneyland. Used the CC there for a few tings), but mostly used cash.
For the cash, I opened a "no ATM fee" checking account that I loaded with some USD.
In China, I used ATMs at the hotels. Those gave you large bills then you could go to the front desk of the hotel and have them break it into smaller bills. When the trip was over, I took all but a few dollars out of the Fidelity account. I still have it open and will re-load it and follow the same plan for any future international trips.
Just be smart about the ATMs that you use and the places you give your CC. Use ATMs that are attached to a bank or reputable place of business. Don't hand your CC to someone for them to walk away with.