The exact wording of the AFM would help, particularly as older 125s used to be designated either A or B variants depending on the regulatory authority. Thus the AFM may use grandfather rights from the older FAR or JAR for approach speed and/or icing certification.
An icing speed additive could be considered as resetting the safety margin from the stall, thus any small increment for wind/gusts etc would be additive, but this might (should) require that the landing distance is corrected. There should be a limiting speed increment as in the examples above.
See
Landing Performance. Para 4.2. provides guidance on speed additives (15 kts max) and general information on landing distance.
Also see
FAA AC 91-79 Runway Overrun Prevention, but here the speed increase could be interpreted as 20 kts (not all manufacturers would agree), but the document again stresses the importance of considering the effect of speed increase on landing distance.
If the approach is made in icing conditions then perhaps a contaminated or slippery runway would also have to be considered. A ‘fast’ landing in these circumstances may not be acceptable; similarly, any late speed reduction could reduce the stall margin with added risk.
Thus, if flying with icing additive speeds and the conditions require more speed, perhaps the better decision would be to ask ‘should we be doing this’, i.e. divert, and not trying to find a way of continuing.