My last trip from eastern Canada to the northwest involved stops at Sudbury (ON), Wawa, Armstrong, Red Lake, Bissett (MB), Norway House, The Pas, Southend (SK), Uranium City and Yellowknife (NWT). That probably doesn't help you much but just indicates that avgas is available but requires some research. I'd bring a pocketful of Canadian cash because some places don't like credit cards. Your overnight stops should be planned carefully because (as stated by scout) at some places on reserves you'd have to sleep in your 'plane to protect it! Some of the fishing lodges sell gas and might even put you up for the night if they have room. No security issues there. Or just find a nice lake in the middle of nowhere and camp for the night. You'll certainly be eating fish for supper (if that's your thing)!
I could have made fewer stops but wanted to drop in at some of those places.
I'd be filing a flight plan for every leg. Don't forget to take a sat 'phone to amend your flight plan in case you come across that beautiful spot with the giant walleyes and decide to stay for a while.
See the country, take your time, bring your fishing gear and have a ball.