French citizen attending Chinese mother-in-law funeral in China

Hi, my son and I are French citizens, my wife is Chinese, we are all resident in the UK. Her mum passed away last night, my wife is already on her way to PRC. Would it be possible to get a visa on port of entry for my son and myself, if we were to fly to PRC within the next few days? Or what would be the best course of action?

Many thanks