Agree with some of the other posts, but would think a month would be plenty of time, of course all depends on how much time you put in the saddle vs off. When making your way east of BC I'd say stick to highway 16, more scenic then highway one with lots of towns and smaller loops you can take to break up the long highway. Hate to say (and coming from a Manitoban) but the prairies aren't that exciting to ride through. The people are great and a rural atmosphere is a nice change but it's a long haul from the rockies to northwest Ontario. But if you don't like it you can pound it out in 2 good days. Once you get into Ontario you'll be on highway 17 which will take you through some amazing lake country and will eventually lead to southern Ontario. Lots of camping and trails to explore and get off the highway. If you want to fly your bike out air Canada will only ship from Montreal, so if you are pressed for time you may want to cut off the Maritimes but would advise against it, haven't been but everything I hear is amazing!

If you find yourself around Winnipeg and need a place to stay or do some work on the bike, let me know and I'll set you up!

The OP stated he has 5 months to ride around the world. It certainly has been done and can still be done today, but that leaves little time for sightseeing along the way.

In 2008/09 I rode from the east coast of Canada to Ushuaia and back. That’s only North and South America and I basically flew through North America as I knew much of it, I could easily access it later, and the roads/terrain were much easier. Once I reached the Mexican border I slowed down. But I only saw the highlights of Central and South America - followed the first Dakar race in South America for 5 days, Machu Picchu, Ushuaia, etc.... ~65,000 km in 9 months. After I got back my biggest regret for that trip was that I didn’t have/take more time.

During that trip I met others who had goals of reaching Ushuaia and Prudhoe Bay, and were not interested in much else. And they were perfectly happy with that. We all have different priorities.

One could easily spend a couple of years exploring Canada, another couple exploring the US, and never see it all.

10 years since my trip to South America, and I’m planning to go back to see what I skipped over. I estimate that part of the journey alone will take me a couple of years.

IMHO, the OP must decide what’s important for him and plan accordingly. What ever he chooses it will be an adventure.

YMMV, and that’s ok.
Robert