where are you in Florida?? you can find a local Chinese travel agency, pay them to renew for you. ( they will go to China Embassy for express service for you .that is more money, but you save the trip )
$$ can do a lot of things in China Embassy, believe it or not!!
I have never apply online. If you apply online, looks like you have to pick up your passport in HK. So count your days right. Maybe you can call HK Immigration Department for more detail.
If you have relative in HK, you can give permission to a relative to pick up the passport for you. Shipping it back to US would probably be expensive because you would want to mail in the most secure way possible.