We haven't travelled to Western Canada for 5 years now, but on several trips we discovered that a lot of the small towns - especially in the US - have community run campgrounds. Most were a minimal cost, $5 or $10 and often free. Many had electric and water hookups and dumps.
Maybe do a Google search of some of the towns you will be passing through and see what c.g.'s come up. Provincial Parks are getting expensive, especially Ontario.
Another alternative, check out boondockerswelcome.com It might be worth it for you to join.
