East of Kenora, you can head south on #71 to the alternate TransCanada Highway, #11, which is much quieter than the main branch, but as you approach Thunder Bay you need to get back on the main TCH (#17, as Machka pointed out) and stick with it from there all along the north shore of Superior and part of Georgian Bay to Espanola. At that point you have the option of heading south and taking the ferry across part of Lake Huron/Georgian Bay to southern Ontario, or continuing east through Sudbury to Ottawa on #17, depending on your preference.