Are sizes 16W, 18W, and 20W women's clothing available for purchase in Shenzhen?

I am moving to Shenzhen from the USA at the end of July and will be there for a minimum of 3 years.
Please tell me if I will be able to find these larger sized women's clothing at the shops and/or department stores in Shenzhen. I will be in BoAn District.
If you know the names of any shops or department stores that would carry these sizes, please do share that information with me as well.
Thank you in advance.