Hey Shahfaisal! I live in Sudbury, which is en-route to Manitoulin. You've got a great idea, I love the ride out to the Island!
The highways up here aren't as nice as the ones you're used to, but you'll be rewarded with amazing scenery, and some lovely winding roads.
There are a few websites detailing the different routes you can take. If you have time, check out 1 or more of these loops. You might have to detour towards North Bay, just keep going North on 11 past Barrie, it will take you straight there. All of these loop tours seem to start at North Bay.
http://www.ontario-motorcycle-rides.com/northern-ontario.html
When you are leaving North Bay heading west towards Sudbury on highway 17 (at Verner), I highly recommend you head South at highway 64 for some beautiful rolling rural highway. Lots of hills, creeks, long sweepers, and smooth roads. Stop for something to eat in Noelville! If you continue south long enough, you will link up with highway 69 which will bring you back north towards Sudbury.
Once you get to Sudbury, you can rest for the night, get loaded, check out the local yokels, see the sights. You'll want to leave in the morning to fully enjoy whats coming next. As you head west on 11 again, you'll find that the roads near Sudbury are rough, but it gets better. As you make your way across towards Espanola, there are dozens of little towns, and waterfront vistas to enjoy along the way.
When you hit Espanola, it's time to turn on your Go-Pro and head south on highway 6. This is one of the most beautiful (and fun!) highways I have ever seen. You will literally want to turn around and go back to Espanola just to ride it again.
Once you get to the island, its up to you how to play it! Don't be afraid of the locals, they are very friendly people and would love to hang out and chew the fat. You might even be invited to a BBQ or something!
I hope this helps, and if you want more info feel free to ask. If my bike is on the road I would love to join up with you for a quick cruise while you're up here. If you make it into Sudbury on a Sunday night, it's cruise night and I can show you the spots - meet more riders!