There is a lot of additional fuel information posted on rv.net. But I'll add: We have a PenFed Cash Rewards Vista CC that gives up 5% cash back on fuel every month and we received well over $200 cash back savings for the trip. This card requires a qualifying account and we opened a money market account for $25. We also have a Capital One CC that gives us 1.25% cash back on every purchase. Both of these cards are good in Canada and the US and there are no Canadian transaction fees.
Also as you drive north Gas Buddy information will be limited so don’t count on it to determine fuel costs. Also in a Canadian “city” expect that all fuel stations will have the same price. As a Canadian told me “it’s not that there is any price fixing, it’s just that all the prices are the same”.