I can't access historic flow information for the years before 2011.
Last year it was pretty low. We waited until early Nov. Elaho was less that 35 and Squamish less than 50. Only the lower canyon was run, we decided the middle and upper sections would be not be very fun.
I think 40-80 or so on the Elaho is probably optimum but that is a rough correlation.
I bet that with the warm weather continuing and gauges reading what they are Dipper will be on the high side.
I've heard rumors of people going up there but have not heard the wood situation.
Stefano at liquidlore.com is usually a good source of information about what is currently happening up there.