There is no mandatory official "staying-time" for Quebec or any PNP in any other province. However, you do sign a statement saying that you are intending to settle in that province. If you can be proven to have lied on any of your immigration papers, you can lose your PR.
It is only recently that immigration has started to cancel PR visas of people who are trying to land outside their PNP province and who either admit or evidence shows that they are not planning on settling there. Others have been given their PR but put on watch by the PNP in their province to look into if they do settle in that province and leaving it up to the PNP to report them if they don't.
In the future, the provinces themselves might crack down on this behaviour even more. It is possible that you will get away with leaving soon after landing and nothing will happen to you. It is also possible that Quebec will find you in a year or two or three and ask you since you came through their program, what attempts you have made to settle in Quebec. If you left Quebec a day after you landed as a PR, you will not be able to say that you made any attempt. Therefore, it is safer to start out in Quebec and try to find a job there. If you have been there for a few months and are unable to find a job but get a job offer somewhere else, then you can go ahead and move. If anybody were to ask you later, you can tell the truth, that is, you intended to settle, you gave it a try but unfortunately it did not work out for you there.