Those 'No Overnight' signs are a CYA..a way to move people off that seem to be parked there for more than a night. I have never..ever..been asked to not park at a rest area or other bit of real estate. There a number of awesome map books for BC, or even just Google Map it..and 'drive' the area you are wanting to overnight in...find a side road going away from the highway. The biggest thing there is turn around space. The biggest thing for people is the 'fear factor'...what about people, bears, wolves, cops, the dark, the campfire, the bugs....and, for some, these are legit fears. So..when I say..stop worrying and just go do it...I am not minimizing your fears. But...give it a try. Please.
Gary Haupt