Agree with your plan to cross at a smaller, less busy crossing. They are generally more casual and quicker to cross. We crossed at Sherwood in 2016. If I remember correctly the first 20 or so miles north were kinda worn and we drove slower for a while - this trip is no race!
Our route then angled northwest across Saskatchewan and we worked our way to the north of Edmonton, avoiding city traffic.
Tough to find places to boondock but as others have said, many towns have small city campgrounds and generally the Canadian provincial parks are very nice and well-maintained.
Enjoy!