MJP,
Such a long float to me is an indication of a slightly high approach speed.
Question - at the end of the float ie just as the whels touched the ground were you able to raise the nose further and then after touchdown, hold the nose wheel well off the ground?.....not easy in a crosswind, I know.
If, you were fully in control of the aircraft as the speed reduced during the float then the next time, I would as a passenger to acurately note the speed at which the float commenced (which will be slightly slower than the approach speed and also not the speed when the aircraft touched down). Compare these speeds to your approach speed and then I think you will find that you will be able to reduce the approach speed slightly. Best done in 5kt increments.
Note also that for a powered approach where you keep some power on until touchdown, you have some extra airflow over the tail. Thus for a glide approach, add on 5Kt to the approach speed.
Once happy, try some low hops to build confidence in flying 1 inch above the runway surface.
Regards,
DFC