Fill a glass or container with as much ice as you can pack in it. Then fill the glass or container with water to the brim. Now, let ALL the ice melt and report if any water overflowed the glass or container.
I was challenged with that years back and the level of both remained the same with no over flow of ether but what a grand experiment in today's time for those who haven't experimented giddy up. .... "BOO"
Doesn't matter what size the ice is. It will displace the same amount of water when placed in a container of water in a solid state as it will replace when it melts, therefore the water level will remain the same in the container that it is in.
If you fill to the rim with ice that is right. If you fill to the rim with water so the ice is higher than the rim it will thaw to rim level. Even though water expands when freezing it is the same amount of matter in either State.