Speed and agility are definitely to your advantage as you make your way closer to the tree. The shield definitely helps as well. Wouldn’t be good if one of those branches gave you a good thwacking.

With the casting of Aresto Momentum the tree finds itself suddenly slowing down, its movements having become sluggish. Then BOOM it is hit with an Immobulus and freezes completely.

Better make your way through the hole by the roots before the Whomping Willow wakes up.