Will you be launching out of Cap Sante or Washington Park? If Cap Sante, the sling launch operation hours would mean you are in the water by about 5 PM at the latest, which is plenty of time to get anywhere in the San Juans before dark this time of year. If starting later from Washington Park, the options of James or Watmough are good ones - James has a nice new (longer) dock, and a dock destination is always nice for late starts, so as not to have to bother with a dinghy late in the evening if you want to get to shore. As suggested, Eagle Harbor is great, 14 free DNR buoys to discourage anchoring (to protect the eel grass), and 4 more buoys just south at Cypress Head, depending on wind direction. Lots of small anchorages in these parts too, if you are comfortable anchoring. A little further than James would be Spencer Spit if you just want to grab a buoy for the night...it's probably my least favorite of all the state park anchorages, although others are fond of it, so it's worth a try at least once. Getting a late start out of Twin Bridges (near Anacortes), the 6nm to Cap Sante Marina itself is a frequent first overnight stop for me - lots of dining options, a grocery store to get provisions for the trip, and shore power to run the electric heater (it is still chilly at night this time of year). Also a large West Marine store across the street in case you forget any marine necessities.
Hope to see you out there - I too will likely be cruising around off and on during the 2 weeks prior to FH. Or possibly after. All depends on work priorities.
-Mike