Currently you can get 50% Delta bonus miles for transferring to Delta. (or 40% rebates in Amex points)

Delta flight to China is generally 70,000 miles x 4 is 280,000miles.

So you can transfer 187K points to Delta(should be 280K miles)

or you can do 280K points to Delta and wait for the 40% rebates in couple months.

I think it might be quite tough to get 4 award seats for January since it's pretty busy early January. I just checked Delta for you, no low mileage award seat until January 9th.
I checked continental, there's some seat available but direct flight(none)