According to the ASTM, platinum RTD’s can measure temperatures from -200°C to 650°C. (IEC says -200°C to 850°C).
You must consider the temperature limitations of all the materials involved, where they are applied, and the temperatures to which each will be exposed.
A few quick examples to illustrate this point:
TFE Teflon should not be used for wire insulation if it will be exposed to temperatures above 200°C (250°C for some).
Moisture proof seals are commonly made with various types of epoxy that generally have limits below that of the Teflon insulation.
Many wire insulating materials become brittle at subzero temperatures and therefore should not be used for cryogenic work.
So state the intended temperature range right up front and let the applications engineer assist you, especially since it may affect the materials chosen for internal construction of the probe.