Those islands are France. We had our honeymoon in St. Pierre. It really is a neat place and I'd recommend going. Don't forget to stock up on wine! ATC is only the tower at St. Pierre (no tower at Miquelon - not sure about customs as we didn't land there). Once you leave the vicinity, you're handed over to Gander center.
All they'll care about when you land is your passport. No prior permission required or advance notice, just file your flight plan and go. File eAPIS leaving (and returning to) the US. Depending on what you're flying, you may be able to make it non-stop if you top off somewhere like Princeton, ME before heading over, but may have a harder time heading back without stopping in Canada for fuel. If you do, keep in mind that you still need to call CANpass before taking off for Canada. Even if it's a fuel stop, you're still landing in the country. You'll want to check the status of 100LL in St. Pierre. When we went they had it, but we didn't take any.
If you're going to head to St. Pierre, I would highly suggest that you also make the short hop (from there) to CYYT and check out St. John's, NL. A truly wonderful town with some of the nicest people on earth, and excellent food.
Icing up there is nothing to fool around with. Also, it is often foggy. Make sure that you check the weather and have plans for an alternate.