I think you have the same idea of boondocking that I do and understand what that word means. Parking in parking lots of stores and truck stops is not boondocking, but urban parking. Yes, it is important to do so by times to get rest.
In many parts of Canada you can boondock. Newfoundland has more such places than most provinces. I can pick out those places in other provinces because I can recognize types of human usage, things that say there is no single property owner. I am much better at this in eastern Canada than in prairie or western areas, but I know they are there.
I've never googled up the words 'free camping', but I think there may be places to find this way.
:C