What would happen to this graph if the bond angle of water molecules were 109,47°?
The dipole momentum would decrease from 1.85 [D] to about 1.38 [D], if I did well the math.
Would ice still float?

If the bond angle changed you would need to play around with crystal stucture. The crystals of ice are well known.
http://en.m.wikipedia.org/wiki/File:Hex_ice.GIF

It determines the density.

The bond angles that oxygen makes are pretty much the same in water ethanol ether etc.5

Of course, it is worth mentioning that ice has a number of different crystal structures modulated by phase transitions that occur at various ranges of temperature and pressure. It's certainly possible to modify the bond angle by changes in state variables.

The fact that ice floats in water at ambient surface pressures found in nature has profound implications for the evolution of life, given the possibility of "snowball earth" events early in earth history.