Northern Shores of Ontario!
If your travels take you through Kilarney you need to hit the fish and chip truck there. They will blow your mind. Just drive along the lake until you see it, Kilarney is small enough that everything is easy to find. If you go on a day when they happen to have caught some Pickerel it's like winning the fish lottery.
Well- I'm sure the Bruce Peninsula has some great options, although I'm not very familiar with that area.
Northern Ontario is not a foodie's paradise.
Algonquin has Bartlett Lodge or Arowhon Pines for nice meals. It think Bartlett makes more of an effort to serve local food and is more creative (mind you I haven't eaten there recently).
Lake Superior and Pukaskwa- hmmm....I can't think of anything to be honest. The best meal I had in that region was a greasy spoon breakfast after backpacking 30 kilometres the day before. The parks themselves aren't developed.
Maybe something has opened in Wawa? I would phoned Naturally Superior Adventures and ask them because they might know of small places in towns like Rossport etc.- the sea kayaking towns that get some tourists in summer.
In terms of local food- the north shore of superior is rocky and not great for farming. Moose meat? fish? well, you might hit blueberry season.
It is a beautiful drive, though. and some of the beaches between Sault Ste. Marie and Puk are stunning and almost deserted, so a picnic would be in order.
I'm sure the Sault has some decent restaurants as does Thunder Bay, if you get that far.