We were there Sun/Mon this weekend and only saw two other groups launch. Then, not another soul our entire time on the Westy section. It was nice to have the ramp to ourselves on Monday, but both days were full according to the calendar.
You don't get a refund if you cancel. All you can do is move the launch to another available date (considered a 'change' to the permit and you only get two of those) in the two month window. There is no other penalty for a no show. You cannot carry it to the next year if it is late in the season, tried that last year.
An option if you can't make it is to change the alternate TL to a different person (you cannot change the TL) and have them reimburse your permit fee. That way, the original person isn't out the money and the permit goes to a good home.
"Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover." - Mark Twain