OBN, the chart you linked on top is for "Aerodrome Reference Code" not approach CAT. The stated approach speed is what gives the Approach CAT.(Ref Jepp Intro-chart glossary, p 2). Jepp is kind enough to seperate TERPS from ICAO CATs. TERPS uses Vref at MLW as ICAO uses Vat (speed at threshold). As for Canada, yes the text says use the actual LW Vref (which might allow to drop one notch) but the example provided is one UP. If you ever dealt with TC, you know there is a lot of "interpretation" and I would not test them on going one notch below. My operator classified each of our types as one, and only one, CAT. Makes sense to me.