The only think I know of is the American Bald Eagle Foundation's festival, November 12th thru the 19th.
https://baldeagles.org/alaska-bald-e...ival-schedule/
I would go to a festival, but usually I prefer to avoid crowds and not be a tourist with a guide.
My first thought is rent a car and go before the festival gets underway:
https://www.travelalaska.com/Destina...0Preserve.aspx
"The river "flats" of the Chilkat River along the Haines Highway between miles 18 and 24 are the main viewing area for eagle watchers and considered critical habitat in the preserve. Bald eagles are attracted to the area by the availability of spawned-out salmon and open waters in late fall and winter."
There are several guided float trips that are fairly inexpensive also, I am not sure I would want to take my 500mm on a float trip. With a little research I bet there are other guided tours as well. A good plan might be to take a guide on day one to get the lay of the land and drive yourself others.