At about 50 kt, the blanket of snow sheared off in what looked like a single piece and the takeoff proceeded normally.
Not going to get into the discussion of Type IV fluid failure, but you should be aware that Type IV fluid is a non-Newtonian fluid, meaning that the viscosity decreases as shear stress is applied. What that means on an aircraft is that as the speed gets up to around 80kts, the layer of fluid will slide off the wing, taking any contamination with it.