Permit reservations for each year are done by lottery and the lottery isn't opened until the end of December or Early January if I recall. I always go off season so I haven't had to try to beat others to get the permit I wanted. Early Spring and Mid Fall permits are picked up easily in my experience.
Permits become available end of Jan. It is first come, first serve. The lottery only applies to a few large lakes that have motor permits. Sign on to the permit site the first day it opens and I would think you'll be able to get nearly any permit you want,
Waterdog, How early in the year can one go without a permit? I think its Oct. 1st when you can self register. I'd think the first couple weeks of october would be a nice time to go. No bugs, no permit required, not too hot, and usually not rainy.
I think you could sign in directly at the entry points prior to May 1. You can check out all the requirements at www.recreation.gov. I'm no BWCA regulation expert. I have been there in late April and signed in at the Ely ranger headquarters. I agree with Quinn, if you get on the site and sign up early in the year, you have an excellent shot of getting the quota permit you are looking for. Plenty of solitude on Spring trips, but you need to be prepared to open a lot of ports, possibly every one, to get through. The majority of my trips are October and you wont see many, if any, people once you are a couple ports from the entry point. That's my favorite time to be there. I may be headed back up there this October in fact for a two or three week trip.