I have to agree with Soundguy, at least for Ontario parks. I'm sure experiences will vary across the country. Around here, the use of gen sets is rare. I can't even remember the last time I saw or heard one in a provincial park.
I find sites here (Canada) are more spaced out and private than state parks. Many of the state parks we've been to in the northern US are wide open fields surrounded by trees. Sites are stacked tight with little to no privacy, much like a koa. In Ontario, a typical site is spaced with natural forest between sites and lots of privacy, hence the need for long extension cords. I carry the factory 25' cord plus two 25' and a 50' and have used all. It's rare to use only the trailers 25'er.
