I've done 3 May solo's in the Q, two of 19 nights and one of 12.  Of course it all depends on your interest and personality, but here is a list of things that might be helpful.  While I know you are interested in meeting other folks, due to the relatively lower concentration of people there at that time you just may not.

1.  Be prepared for horrid weather.  May is one of the most beautiful times to go, but also bad weather can come with a vengeance.  I've had a few times where it has been 35-40 degrees, windy, and rainy for two days on end.  So it is worth the extra effort to carry a sturdy, comfortable tent.  Sometimes the weather is perfect, but you have to plan for the bad.

2.  I bring lots of books.  I read a lot anyway, but I bring 10-12 of them each time.  If the weather is bad, or I'm starved for talk, a book is just the thing to exercise my mind.  If some dumb song gets stuck in your head, a book can take it away.

3.  Rubber boots.  Often the portages are small streams and you are walking through are water as much as land.

4.  If you want, you can enter prior to May 19th.  No permit is required then.  You need a RABC permit and to pay the box, but you can go permit free prior to that time.

5.  Again, it depends on your personality, but I find it helpful to travel every day that weather allows it.  I get bored by myself in a base camp.

6.  Stay near shore when you paddle big lakes.  With cold water, unpredictable wind and weather, I'm sure you know this.  I often take the long route around just for safety purposes.  Twice I've nearly been caught in big blows that came without a warning, and I was glad I had an island or point to hide behind.

7.  Be sure to bring your canoe all the way up on shore when you stop.  At night I tie it to a tree as it is light and could blow away.  I don't want to be stuck, canoe-less, on an island.

Just a few thoughts.  Have fun and enjoy yourself!