HI V,
What makes you saying that? I know you are not an expert, but there must be a reason why you saying that if I'm legal for at least one year (which I am) then I'm OK. What I was thinking if whether the immigration officer will ask about what is our current legal status and if they discovered that I'm overstaying my visa then they will reject my canadian PR application.
Remember not all cases require an interview. But don't take so lightly the idea of overstaying in the USA, consider it as a last resource since you don't know if you would be ever in need to go back in the USA. Things might not go as you expect in Canada and you would wanna come back. And not just that, let's say you decide to overstay and your process keeps going well to immigrate to Canada (wich it should) and for some very bad luck, you get in an accident, or you are detained in a ICE inspection point, then they catch up with you, and your family, they may detain you all in a prison like facility (and you wont be together) before deporting you. And in the meantime you'd lose your opportunities of immigrating to Canada, you would be banned out of the USA and you would be forced to go back to your country. Needless to say all the awfull experience you, and your family would have to go tru. Of course sometimes they'd give you the option of leave the country by your own, but that'd still leave you with very little time to plan where are you gonna live.