My wifes 6s+ get the update straight away, but my 6+ do not. So I unpair my watch, use her phone to update my watch (thanks for the new multi pair function, I don't have to unpair her watch). Just after the update finished (without really pair up with her phone), then I can re-pair it with my 6+. It took sometime, but for me, better than wait.
If you have any friend have 9.3 and 2.2 already, you may ask for their help.