That's a bit paranoid and overly cautious imho. For starters, powering it off doesn't remove the current. You would need to remove the battery and any axillary batteries. You would also need to remove the lens as there is still current between the lens and the body. That level of condensation is nearly impossible to achieve unless it was really cold and the house very hot and humid. I live in Bangkok where it hits 41c and have went from AC (24c) to out outside (and vice versa) and have never seen condensation.
I think Chuck Westfall had a write up a while back about sleep mode stating it was pretty close to powering it off from a consumption perspective.
For me, I turn it on when leaving for a shoot or walking around. Once I'm done for the night (shooting, post processing, etc..) I shut it back off. I'm not worried about a switch or anything, just saving a bit of battery life. The sensor cleaning is a bit of a plus too, but not really a concern.
Its no big deal. I just turn it off if I see my glasses or the lens mist up