I wish I could answer your questions better, maybe someone who knows the area you are talking about will come along. All I can tell you is that in Ontario the 400 series highways are equivalent to Interstates and they do have rest areas where you could take a nap. 17 is a main east-west highway, I think you will find rest stops, but we need someone who knows that highway to tell us for sure.
Licensed dining just means that the establishment has a license to serve alcohol with meals.
There is some different designation for diesel in Canada, but whatever they sell at service stations will be equivalent to the US #2. (It may be more doctored up for the cold during winter though).
Hope you enjoy your trip. I've heard good things about that area (NW Ontario), but we are days away from it down here in the extreme south of Ontario.
OntMont (John and Donna)
2005 Montana 3670RL
2007 Silverado "Classic" 3500 DRW 4x4 CC D/A.
2001 Border Collie to ride herd on us.