Dreamspeaker is great, the authors are wonderful people too.
The area is a bit drier and more mild than being in Seattle or Bellingham generally at that time of year. But that is certainly a generality. But generally you should have any the most popular spots nearly to yourself and the weather will still be mild and mostly dry. Of course getting worse as you get into October. This is my FAV time to spend in the San Juans, Gulf Islands, Sunshine Coast.
You will get more rain if you go up the inlets, like to Princess Louisa and Chatterbox Falls. But it is one of the most beautiful spots on earth. Do it anyway.
A 2 week trip from Seattle aboard a J-35 and you will just not have the time to worry about going thru Seymour narrows. 4 weeks maybe. But you could easily while away a month with out getting much past Desolation Sound.
From Seattle to San Juans minimum 1 long day
day 2 for customs at south pender and into the gulf islands
day 3 somewhere near Nanaimo
Day 4 cross over towards Egmont and take a hike to check out Skookumchuck rapids
day 5-6-7-8-9 explore sechelt and Jervis inlets and then to Chatterbox
day 10 back towards texada island/powell river
11 cross Strait of Georgia to Nanaimo, you may be ready for a good night out by now.
12 Customs at Roche Harbour (store will be open, restaurant I think closed)
That would take two weeks by the time you got back home and you didnt even make it to desolation sound. And I wouldnt even consider this a leisurely itenerary. We used to do an annual 10 day trip on a trawler (8kts) and that only covered Bellingham to Desolation with one side trip.Did that 8 times I think.
You could add two more weeks in for Desolation and the areas just slightly north and never have to worry about Seymour Narrows for a 1 month trip.
Be sure to get a Canadian License if you like oysters, there are tons by the time you get past Lund. They literally become a hazard they are so plentiful on many beaches, don't wanna cut yer yittle toesies. Not sure what fishing or crabbing season is on then. Great bottom fishing nearly anywhere after the Gulf Islands anwhere up there in the inlets, desolation, redondo Islands, butte inlet.
Tenedos Bay at Desolation is my personal FAV. Oysters, big Lingcod, warm lake with a warm stream running thru the forest down to the beach.
I wanna go. Well, looks like we will be doing a charter from Phuket to Langkawi in October, but I still miss home!
-edit- Have to add the one wraning about Skookumchuck. DO NOT ATTEMPT WITHOUT CHECKING THE CURRENT GUIDE specifically for this spot. Huge current here to. But not so long in length as Seymour Narrows. You do not want to be sucked thru here on a sailboat.