Thank you snow, you make a good point. At least we have a while to think it through! The full name for George in Greek is Giorgios as you said, but it is always and unfailingly turned into Giorgos (Yorgos) which sounds so different to George in my mind! Meh!
I don't think it would confuse him, nicknames don't seem to cause problems and gradually he would just know that he has different versions of his name, in the same way that he will speak both languages in different settings. I guess you could get him christened whatever as that's not a legal ceremony, but not sure about the passport thing. I'm inclined to think not unless he was to change his registered name. But not sure. If your surname is Greek then I would go with Giorgios or whatever, and call him George as a nn. Then he has both. But up to you.
Currently pregnant with dc1 who I have tentatively agreed to name after one dh's parents, as per old style Greek naming traditions.
In essence, I have no problem with this. I know what it will mean to the in laws, who I have a really loving relationship with. Plus we live in the UK amd they live im Greece and it goes some way to forging a connection to their grandchild who they wont see as often as their other grandchildren who live there. His mother has a beautiful name, which carries a range of nn possibilities which are different from the nickname she goes by. I'm sold on that. However, I don't love his dad's name, which is the Greek equivalent of George.
The name George I like. Not love but like enough to go with it. Though we both speak English and Greek at home, I know I'd end up calling the dc George and not the other version. His dad and that side of the family would all call him the Greek version. Would it confuse him? Also does anyone know if I could register him as George in the UK and christen him with the Greek equivalent in Greece (just for ceremonial purposes or for if he ever wants a Greek passport in the future)