For example, is the lewis structure for water constant even when it is in a solid, liquid, or gas phase?
Lewis structures are a representation of the atomic connectivities and electronic lone pairs present in an individual molecule of a substance. The molecule of the substance does not change in these states, so the Lewis structure would remain the same.
What does change in these states is the way individual molecules interact with each other. If you were to draw a diagram of how multiple Lewis dot structures of the molecule interact with each other, that would be different for these different states.