According to Appendix 2 to EU-OPS 1.430 (c),
The category defined for a given aeroplane shall be a permanent value and thus independent of the changing con-
ditions of day-to-day operations.
.
In FAR-land things are different, though. They seem to have a provision requiring the PIC to choose a higher approach category when, as in your example, the approach speed exceeds the respective category.
I remember the question has been covered here before. A search might help.