It will not work. I have flown a helicopter with fixed floats on contracts in swamp land. The floats are only good for a few hours in the water.
Helicopter floats are made of rubber and filled with air...unlike FW floats which are made of metal and float like a boat.The problem with leaving the helicopter floating is that the temperature of the water after a few hours will make the air condense in the floats and your helicopter will slowly sink.
Go with Redeye's or Aesir's solution is even better.