Hi we did the trip in 2010 from Prince George to Newfoundland with a trailer. Traveled from June 1 to first week in Sep. Traveling with a trailer like this is not the best why because of all the setting up and take down as traveling most days, but otherwise really enjoyed ourselves.
We made Newfoundland our top goal and sure glad we did, five weeks there and that was not long enough. A fantastic place for raw scenery, people. Traveled fairly quickly to Niagara Falls, spent a couple of days there then crossed into the states which I highly recommend. The scenery and smaller towns through upper New York State, Vermont, New Hampshire and Main are a must see. Avoided the interstates and stayed on the secondary highways and roads. We did not go into Boston or New York, stayed to the north. Our route followed the south shore of Lake Ontario, into Lake Placid for a day following route 812. From Lake Placid around the south end of Lake Champlain then across to Lebec Main staying north of Portland. At Lebec stayed over at Sunset Point Campground, get the last site fantastic views and feed the fish in the pond. Why at Lebec, well go down to West Quoddy Head Light then you will be at the most eastern part of the continental US then if you go to St. Johns one can pick off the most eastern part of Canada and North America.
Back tracked a bit and went into Canada at Saint Stephen heading for Saint John then onto PEI. East of Charlottetown we stayed at Vista Bay Golf course which has a campground way up the hill giving one a fantastic view of the water. The campground is basic but with plugins and shower. We stayed there a few days and PEI being small enough took in a lot of it with day trips so not having to drag the trailer. Spent Canada day in Charlottetown the seat of confederation.
Back across the bridge and onto Baddeck and took in the Alex Graham Bell museum, a must do.
Now a must do is the Cape Breton trail but leave your trailer in a campground as the road can be steep and narrow and easily toured with a couple of day trips. Do not drive it in one day as too much to see. We drove one half one day then the other the next. We stayed in a KOA on the way to North Sydney to catch the ferry to Newfoundland and did the Cape Breton Trial from there as the truck needed work and the garage gave us a loaner car to use for the trail. Saved a lot on gas with the loaner. We then also booked the ferry. Had to wait a few days for the truck and ferry.
Newfoundland, well just do it all and spend as much time as possible. We even got over to Labrador as the ferry is dirt cheap. At the time $45 for a 11/2 hour ferry ride. We stayed in the parking lot at the government wharf in L'Anse-au-loop right on the water. At the time there where two huge ice bergs grounded in front of us and I would get ice that washed ashore for my rum and coke. Only traveled as far as Red Bay leaving the trailer at the wharf.
Getting on and off Newfoundland is expensive but don't even think about it, just do it. Make Newfoundland your objective and take as much time as possible. We took the short ferry over and the long ferry back. While on Newfoundland watch for moose on the road, take in the local food and entrainment especially in the small towns. Definitely take in the boat trip up Western Brook Pond in Gros Mourne Park and travel to St Anthony, scenery all the way.
Along with everything else to see go to Twillingate and Crow Head for an evening diner show that can't be missed if in the area. Hope that show is still going, they weren't exactly spring chickens when we were there.
Hope this helps, message me for more if needed. On our whole trip never a campground and never had an issue.
Do Quebec city the old town and if Touring Ottawa the Municipal campsite west of town is great and you can get rides and tours into town from there. We hit the tourist centers in every province, state and city, lots of information there.