Recently got my green card through the diversity lotto scheme and entered the US to 'activate' it which I had to do within 6 months.
My actual green card is said to turn up in the post in a few weeks.
I stayed a month to get a feel for the country and to travel a bit - see a few states etc.
I've returned home to sort out all my bits and pieces in preparation to permanently move to the US including saving as much money as possible, selling my house etc. I was thinking of returning to the US permanently in about 8 months at which point all loose ends will have been wrapped up where I am now.

Does anyone know how long I have before I have to return to the US?

I know that I'm not supposed to travel (be out of the US) for more than a year at a time to prevent my residency status to be revoked - that's all well documented and I get that part - this won't be an issue as once I move there permanently I don't intend to leave again.

But I still don't know specifically how long I can be out of the US since activating my green card.
Does anyone have anything specific on this?

Thanks in advance.
Piet