Good idea on doing something before the fish are in, everything gets busy after that.
Do you want to avoid established campgrounds? I like them for weekend trips if I can plan early enough in advance and reserve a spot, take the guesswork out of it. But I realize they are not for everyone. I like Trail River CG and Primrose CG on the lake.
Cooper Lake is also nice if the road is not total crap, depends on how bad the winter was up there.
The Denali Highway is probably too far for me to go due to time constraints, but I could be convinced to head up to Hatcher Pass, love that area but don't know any real good spots other than the camping along the road to the pass.