I remember the Seattle group being pretty good about three or four years ago, but I haven't really involved myself in the bigger NaNo community the past couple of years. I just haven't had the time or the energy for the bigger meetups. I'm sad that you had bad experiences with them. :(
It seemed to be run by a few bffs around college age. All write-ins / meetups were downtown and their opinion on non-downtown gatherings were 'you can plan it but we won't put it on our calendar or help you get the word out in any way because it's not OFFICIAL'.
Oh, yeah, no. A few years ago whoever was running it was making a point to have usually 3-4 write-ins going at a time, at different coffeeshops and such, all on the calendar. On the grounds that smaller neighborhood-focused write-ins were probably more manageable than single big ones. (The exception being the November 1 midnight write-in which was usually huge and done somewhere like Southcenter.)
That's super unfortunate. :(
My biggest piece of writing advice: stop in the middle of a sentence or paragraph. I've found it does wonders for me. I don't write until the 'thought' (as it were) is done but I stop while I still have ideas. It gives me a place to dive in the next day without hemming and hawing over 'what' to write. Once you're in the groove, it's easier to keep going.
I learned this from one of the classic authors. I forget which, tho. :\ But it totally works.
I do often try that. I've also been using some of what I picked up from Mary Robinette Kowal at SIWC this year, about how to deal with writer's block. So far it seems to have helped.
(Also, if you want my SIWC notes, btw, as a fellow writer, feel free to peruse them. Some of the workshops, the notes haven't been great, but for some of them they've been pretty useful. SIWC'17: Diagnosing Story Problems are my notes from Kowal's workshop on writer's block and editing.)