Methanol-water mix freezing points - clarify contradictory online data > 60% w/w?
From Solid-Liquid Phase Diagram of the System Methanol-Water by G. A. Miller and D. K. Carpenter in J. Chem. Eng. Data 1964, 9, 3, 371–373 (July 1, 1964) [https://doi.org/10.1021/je60022a017]

&quot;A solution of methanol and water that is methanol-rich tends to form
a glass when cooled below the melting point. The liquid is very
viscous at such temperatures (below -100° C.) because of the presence
of hydrogen-bonded polymers. Because it is difficult to induce
crystallization, the melting point is determined from a warming curve.
Much of the wide divergence of melting point data for the composition
range of 55 to 95 mole per cent* methanol results from the use of
cooling curves.&quot;

* by a back-of-a-napkin calculation (assuming 32.042 g/mol MeOH and 18.015 g/mol H2O) the mole percentage mentioned is approximately 68% to 97% methanol (w/w).
Further - successful - online research was inspired by a comment; it appears the failure to find information with common search terms was due to a language difference. It seems specialists (presumably physical chemists) use &quot;solid-liquid equilibrium&quot; or &quot;solid-liquid phase diagram&quot; in documents which may completely exclude the term &quot;freezing-point&quot; - such as the publication quoted above which answers the original question.