Here's an outside the box solution....
Remove the floats and turn it into a land house near the water. Or maintain the illusion by having a small moat around it or a lake in front of it.
It could be set up on land beside a marina or waterway somewhere and still retain all the atmosphere of being the Houseboat. In fact that's probably what you would really need to do in order to use it as a museum to ensure it could be used all year round.