Added Potassium Sorbate
Before leaving for the weekend at the cottage, I put the carboy of Vidal Icewine in the fridge in order to stop all remaining fermentation (however minor).
Today, about 72 hours after I put the carboy in, I added 3.4g of Potassium Sorbate in order to prevent any re-fermentation of active yeast cells.
According to the BCAWA site, 0.18 g/l is supposedly the threshold at which the taste of the Potassium Sorbate can become detectable to taste, and so I wanted to hit this number without going over.
As for next steps, I'm going to keep this in the fridge for a few more days, then filter it later, before bottling.