Good evening Ron,
I didnt see this post earlier so sorry for not replying earlier. We've been out east a couple of times and the three campgrounds I can heartily recommend are:
1. Cape Breton Highlands National Park, just north of Cheticamp on the west coast of Cape Breton. Great campground and Cheticamp is a nice little town. The scenery is spectacular and Cheticamp is a great spot to get to from the south, leave your trailer there and take a day trip to complete the Cabot Trail (don't take the trailer on the Cabot Trail, the grades are steep and winding - I saw the results of overheated brake failure as I went along)
2. Fundy National Park in NB, great facilities, even an enclosed dining pavillion with cook woodstove
3. Cavendish Campground, PEI - on the north shore, it was beautiful park but can be quite windy (we stayed there back in our tent trailer days, kind of disconcerting watching your roof sway above you while you lie there!)
We also really enjoyed the town of Bridgewater, but stayed in a cottage while we were there so I don't know of any decent campgrounds.
Enjoy!!
Kasper