The pilot reported that he ferried the straight float-equipped airplane to a grass airstrip for an annual inspection. During landing on the grass airstrip in crosswind conditions, the pilot reported that upon touchdown he applied back pressure to the controls and added power, but the airplane lifted and came back down quickly. The crosswind had drifted the airplane to the left and as the airplane began to slow on the runway the pilot felt the left float buckle. Subsequently, the left wing and nose impacted the ground and the airplane nosed over, coming to rest inverted. The airplane sustained substantial damage to both wings, the fuselage, and the rudder. The pilot reported that there were no pre impact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. The pilot reported the wind as 060 degrees true at 10 nautical miles per hour, and not gusting. The pilot landed on runway 31. The pilot reported that the grass had just been cut, and that it would have been better if there had been dew on the grass. He further reported that the crosswind drifted the airplane to the left causing the left float to collapse. He wrote that he should have returned home and come back the following day when there was dew on the grass and no headwind.