All advice and information? Well, as far as the driving itself is concerned, I've only got 2 words... prepare yourself.
I have driven my motorhome on the interstates in Baltimore and DC, and you are travelling through 2 places where I will NEVER drive my motorhome... Toronto and Montreal. White knuckles at their finest.
In Toronto, you'll face a ton of traffic. In Montreal, you'll face a ton of traffic AND a lot of people who treat the highway as their own race track where everyone is trying to get into that one spot that's ahead of the next guy. There is a new toll highway that goes around Montreal to the south - if I ever need to head that direction, that's where I'll be, regardless of cost.
For places to stay, of course, will depend on that amenities you need. You're not likely to find many places where you'll find a cable hookup at the site, for example. In the Ottawa area, just south is a place called Poplar Grove in Greely. Typical small town park where there are some open spaces that you could set up a satellite. Just a left out of the campground and you can be in the heart of downtown in 15 minutes. About a half hour out of town, between Ottawa and Montreal, is a small town called Limoges where you'll find Kittawa campground. Also in Limoges, not far from the campground, is Calypso water park. Not sure whether it's still open in September, and it's quite expensive, but if you'll only be in the area once in your life, you might want to give it a go, if that's your kind of thing.
Along the way between Toronto and Ottawa, just past Kingston, you'll see an exit (exit 556) for a town called Shannonville. Take a right at the exit and it's a short drive (about a mile or two) to the indian reserve where you'll find the least expensive gas in the entire area by a loooooong shot. Just today I'm seeing prices reported that are 15 cents a litre (57 cents/gallon) less expensive than here in Ottawa. On google maps, I see when you get to the main intersection, take a left and there is a gas station that will have no problem with a rig your size.
1999 Itasca Sunrise