Oh also I forgot to mention we're coming from Sudbury, Ontario
Well that changes everything, any direction out of there would be good. Just kidding, OK maybe half
Heading west would be cheaper and easier for camping. Atlantic Canada is a fine ride and really scenic but there is a lot of backtracking to get down to the States. The US eastern seaboard is an expensive urban mess from Massachusetts southward, with no cheap camping options.
With the Canadian dollar so low right now, I'd stick with your first idea of riding to Vancouver. Riding through Northern Ontario is a tough start, but hey, you're used to it The roads get way better when you get to Saskatchewan. Personally, I would take the Yellowhead Highway via Saskatoon - Edmonton - Jasper over the southern route. The Icefields Parkway towards Lake Louise is probably one of the most spectacular rides in the world. There are lots of WWOOFing opportunities in southern BC particularly the Okanagan.