That is not enough. Doubling won't be enough to retire so my point of return is if I've won significant huge amount of money that can make me live off it.
If I keep on winning but only with small amounts, that won't make me stop and I will keep on returning because I want more.
Don't get me wrong, I'm a disciplined gambler but who doesn't want to have as much as they can if the topic is all about no point of return?