I tried to count how many fly-ins Ive done.......came up with 27 that I can remember, likely a few more if I include moose hunts. In any event, if you are going to go mid August or later, one can negotiate a much better price at many camps as they are slow at that time. A lodge with a tremendous fishery is Cat Island Lodge on Trout Lake, a short 15 min flight out of Red Lake. Cat Island lodge offers an American Plan at housekeeping prices come mid August. Expect 100+ walleye days with the majority over 20". My PB LT came out of there at 33lbs in addition to a 47" NP. The lake is big and offers countless days of exploring if thats what you want or, you can start catching right from the dock. Take in a portable downrigger and depth finder and you will average a laker every 10 min with most over 5 lbs and many over 10.
That said, I rediscovered Lake of the Woods this year after a few years absence. The MNR has done an outstanding job of managing the fishery there.
During our week in mid Aug the action was steady and we caught dozens over 23" including a 29". Despite it being our 1st time in the N-W area (S-W of Kenora) we had no trouble finding lots of large fish. In some respects (ave fish size) the lake surpasses any fly-in Ive been on and rivals the upper tier lakes in quantity. Moreover, most camps are drive to with a few boat in options. Two camps I would recommend are Ash Rapids and, Crow Rock (American Plan only) but, there are many others.