Beer in exchange for legal information, eh? I think I like our Canadian judicial system. 
See, the reason I brought up motor homes is because there are many cases (admittedly publicized on the internet) where a person has lost even at appeal, because he was deemed in control of his vehicle, despite the fact that he was sleeping in the back seat, no keys in the ignition, and so on. He potentially could have driven drunk. Just as an RV owner could.
Different jurisdictions have different laws, and even if the laws are similar often the intrepretation is different, so don’t assume how it works in Canada applies elsewhere.
Thanks. Very interesting… Very informative.
However, my read is that the situation is still dicey - if you are waist-deep in a sleeping bag, head to the passenger’s side, there is no back seat, and some valid legitimate question as to whether you or someone else put the keys in the ignition and turned it (to ACC) then the judge might, by the time you reach a higher court, buy your story.
If you are in any way somehow indicating the possibility that you might have positioned yourself in the driver’s seat while drunk, and the keys are somehwere to be found, then you better get a good lawyer and it will cost you to get off if indeed you do.
Sleeping it off in the back seat might get you off on these criteria. Why chance it? There’s what I like to call the “OJ acquittal” where you go broke avoiding the conviction.
Also, like the USA there is a legal mentality in some areas here that they will charge you and see if the judge lets the charges stick rather than give an “offender” the benefit of the doubt.