Oops, yeah, overflowing shred and to-file bins are discouraging. :-(

With the to-file bin, is any of it "annual" paperwork, where you're just replacing the oldest/last year's paperwork in the file cabinet with the newest/this year's version? You could maybe do a first pass through the pile just focusing on those items, since they don't require much brainpower to file, which could get what's left down to a more manageable level. 5 items a day, perhaps?

And do 5 minutes or a shredder binful of shredding each day to tackle the to-shred bin?