Here, it depends on whether icing conditions are present or not (those take a speed increment of about 20kIAS depending on situation).
180kIAS is a good figure for most conditions and ATC is usually happy with this. Lower is possible in non-icing conditions; turbulence and icing together on the other hand might cause a crew to prefer 190-200kIAS for more speed margin (min speed is typically around 170kIAS in icing).