Seat Foam Shaving
Another do-it-yourself mod for the vertically challenged is to shave down the seat foam, then put it back together. This took about 2 hours to complete, and got me another two inches closer to the ground.
There are also custom seats you can order, but that option seemed expensive so we figured we would try it ourselves before going that route. There are also places that will shave your own seat down for you, but again cost was a factor.
In the end, this worked really well for us and I'm super happy with the new lower seat. If I was heavier, it's possible this would not be enough padding, but so far even on all-day rides the foam is thick enough that I don't notice we took any out as far as my comfort-level.