I think they could do it but will probably fall just short.
The defenses they've played for the most part are playing below average. Currently, only the blackhawks (5th) and sens (3rd) were in the top 15 in GA. The leafs need to play more top 15 defenses. Everyone else was below average to bottom of the league.
sens -3rd
hawks - 5th
devils - 16
red wings - 19
rangers - 21
caps - 21
jets - 26
canadians - 29
the leafs may also decide to trade offense for defense at the trade deadline. They need to play some of the decent defensive teams. They are still the best offensive team though.