Pilot flying reported runway excursion during landing rollout.

Narrative

Personal VFR flight from ZZZ1 to ZZZ for the purposes of participating in Event. I volunteered to bring the Aircraft X into the event for display.Departing ZZZ1 winds were out of the South at 3-4 kts. and I departed Runway XY as a flight with an Aircraft Y attending the same event. Departure included a southbound turn off the departure end; leaving the delta airspace at ZZZ1 to the south. In route the ATIS weather was obtained at ZZZ which showed XXX at 18 Gusting 22 kts.; giving a crosswind component of 14-18 kts. Max demonstrated crosswind component for the Aircraft X is 15 mph which is 13 kts.Our flight separated into 2 seperate aircraft in order to ease the transition into ZZZ. I contacted Tower and advised that I had the weather and requested Runway XX which based on the ATIS was the marginally favored runway over Runway XXL. I was cleared straight in to XX.An uneventful approach led to short final on XX. I was able to maintain centerline without crab and the upwind wing low; giving me the impression landing was still feasible. Upon touchdown with the left main gear touching down first; the aircraft settled onto the right main gear as well. As the upwind wing leveled; additional full left aileron was added; as the left wing wanted to lift given the winds. With wings level; full left aileron; full left rudder and left differential braking applied on rollout; I was unable to maintain centerline.The aircraft was drifting in a crab toward the leeward side of the hard surface. Additional right brake was applied to attempt to arrest the forward motion prior to departing the hard surface which was not ultimately possible. The aircraft departed the hard surface into the grass adjacent to the runway at approximately 10-15 kts. forward speed; coming to rest approximately 15-20' of the right side of Runway XX. In the process of departing the runway; a runway edge light was struck by the right float outboard edge. This did not result in any damage to the aircraft however the light was knocked over.Once at a standstill; I conversed with Tower asking permission to taxi out of the grass. The aircraft was fully functional; without apparent damage and could easily be taxied across a small irrigation depression and onto a flat grass surface that allowed for return back to the approach end of Runway XX. Permission was granted to enter Runway XX and taxi to the ramp.Upon reaching the ramp; the aircraft was thoroughly examined; found to be free of damage. A report was given to the airport ground operations personnel at the aircraft per the Tower request. No additional information was requested;To summarize; there was a RLOC event at low speed 10-15 kts. This resulted in the aircraft leaving the leeward side of Runway XX into the grass adjacent to the runway approximately 15-20' off the hard surface and striking a runway edge light. No damage occurred to the aircraft; the aircraft could be taxied under its own power to the parking area without further event.Appropriate contact with airport authorities was executed and completed. Upon further discussion with pilots on the ground observing the landing; there appeared to be a strong gust just as the aircraft was touching down. The fly-in portion had been cancelled due to strong crosswinds for the event. Contributing factors include high crosswinds for aircraft capabilities. Human performance considerations include judgment lapse with strong crosswind component; a sense of pressure to arrive for the event on the ground due to the commitment; a lack of assertiveness in making a decision to divert due to winds given the social pressure of having another aircraft in the flight.