I fit well in a 16" English saddle. Some of it depends on what type of saddle you ride in. For example I don't have as much issue with a large flat type seat (jumper) saddle as I do a too large dressage saddle where you need to be in the pocket.
I've also found that the placement of the stirrup bars makes a very big difference. Stirrup bars that are set further back, on larger saddles, still tend to give me the same balance point as a smaller saddle.