I figure to be especially careful until into next year but after that I think some things may slip depending on how they come up. It may not be open as long in other parts of the world as that could requires a little bit of apology. For those without a way to watch it but easy internet access I'm afraid you may be caught in a catch 22; you've got access to too much information but not the piece you are looking for most.
Two weeks is plenty of time to see the film.
If you haven't by that point then you probably don't care enough to worry about said spoilers.
If you haven't seen the film yet and do care about spoilers then avoid places like this forum. That's what I did for a few days until I saw it.
Yeah I think after a month there is just so much talk about it it is impossible to avoid spoilers. Plus even if I haven't seen it if it has been out for some time then spoilers are just something that one couldn't care for. After all everyone else already knows Darth Vader was Luke's Dad (I was born in the 80's) so by the time I was able to understand what was going on the information and jokes on TV and magazines were already out and that was before the time of the internet.
So after a month like in Mid January or even February I think we can relax on the spoilers from the movie. If you haven't seen it by then you probably already heard what went on. As it has also been mentioned the movie sort of spoils itself, the surprises really were not that much of a surprise.