You would have to hike on much of the Trans Canada Highway which is almost 5000 miles long. Gas stations are sometimes over 100 miles apart, let alone camping sites. You would likely have to either stealth camp (i.e. farmers fields) or have some sort of escort such as a motorhome. There are lots of great campsites but in the summer they tend to get full up fast. There are government provincial campsites as well as many private ones. Of course motels may be a good option too.
I am sure people have cycled it but I have never heard of anyone actually hiking from one end of Canada to the other. The terrain varies a lot . Here in BC we have mountains and wynding roads whereas on the prairie provinces the ground tends to be flat and the roads are relatively straight. In the prairie province of Saskatchewan they say you can see a dog that ran away two days ago
Good luck, and don't try it in the winter.
I should have mentioned that there are a few who have jogged across Canada. I didn’t include those as they seem to always have an elaborate support system. They don’t have to carry anything.
Since I posted I found this site:’
http://www.walkcanada.com/about.phpI guess he made it.
Howie