Are there special safety considerations when flying to/in Atlantic Canada?
Plan for unexpected weather amid limited options for dealing with it.  I've flown a number of times between Newark (EWR) and Halifax NS (YHZ), Moncton NB (YQM), and St Johns, NL (YYT).  It can be quite foggy and windy and in the cold months braking action can become a factor.  A lack of options can be problematic.  When we flew EWR-YHZ we often chose EWR as an alternate and I've turned around as late as talking to Halifax approach as braking action become NIL and we didn't have gas to wait it out.  Going out to YYT we'd only have enough gas to get to Gander (YQX) if we couldn't get a good approach in at St Johns.  I flew a capable jet under IFR with Cat II approach capabilities so your concerns will be slightly different down low and VFR.

Although you are VFR, I'd play by IFR rules as alternates and fuel is concerned.  Plan enroute alternates and carry enough gas to get to your destination and get to your second choice with some gas to spare.  The weather can turn quickly and the fog in any of the maritime airports can be thick enough to turn even IFR GA planes away.  Have a plan to be able to get on the ground somewhere else.  Also consider how fatigue will play into your decision making once you are out there.