Canada can and is a good alternative to the US side, but it's not necessary to go that far in May or June. Plenty of walleye on this side. Yes, some charters do go over the line starting in mid to late June, but that requires licenses for the customers, etc. Generally speaking, no reason to go over there until July unless you want to get the license and yes a little better fishing on some days. It's always the same - first you have to find the fish, then find the active ones, then what they want.