John Fields wrote:
(snip)

While the boiling point of water is dependent on pressure, the
freezing point, I believe, is not.

At least, not to a great extent. I don't have any data to support
that position, but I'd love to see some, if it's out there.

If you are willing to consider extreme conditions, not only does the
freezing point change, but there are many ice phases, each
structurally distinct and with temperature and pressure boundaries.
http://www.lsbu.ac.uk/water/phase.html