It's impossible to compare the relative strength of divisions if there's no inter-division play. I'm not convinced the North is as bad as everyone says it is. Dom L. did an analysis where he found that of the top ten teams in the league, eight of them have faced, in aggregate, below-average competition--only Carolina and Washington have faced an above-average schedule.
Based on strength of schedule, the Leafs and Bruins have a pretty much identical expected winning percentages. Both teams are outpacing their expected numbers, but the Leafs' margin is three times larger than the Bruins. Vegas and Tampa both have easier schedules than Toronto, yet the Leafs are still first in the league. Those teams get to feast on objectively terrible competition for half the year--the California teams plus Arizona in the West, and Nashville/Columbus/Detroit in the Central. The Leafs get only two outright bad opponents (OTT and VAN) and a whole lot of middling teams--it's harder to rack up points when you're facing fewer teams that are outright tanking or rebuilding. The fact is that they held McDrai to one assist in three games, and that's impressive no matter how you slice it.
The middle four in the North (EDM/CGY/MTL/WPG) would have to be extraordinarily bad for the Leafs' 18-4-2 record to mean nothing in the grand scheme of things. This is a good team that's playing better hockey than in previous years--their results aren't exclusively the product of weaker competition--and they're finally free of the Atlantic division. This isn't to say that they're the best team in hockey right now, but at the very least they should be taken seriously if/when they reach the final four.