First of all, find out the distance of each route, and divide it by the number of days you want to cycle.
For example, if the distance is 4000 km, and you want to take 6 weeks (6 weeks * 5 days/week of cycling = 30 days). 4000/30 = 133.3 km/day.
Is that the kind of distance you want to cycle each day? If not, then modify your route accordingly.
And I'd be inclined to go with mev's suggestion of doing Maine/New Brunswick/Nova Scotia/PEI/Newfoundland/Eastern Quebec route. That's one on our to-do list.
