In almost 5 years on the 744, I've never had to use wing anti-ice.
However, in the rare cases where you do need it, holding and descent should be done with flaps up, and flap extension delayed as long as possible to minimize your time exposure to icing conditions without anti-ice available. Generally, approach holding is at a weight where max holding speed can be accomplished with flaps up. If icing is a problem and holding speed is lower than flaps-up maneuvering speed, tell ATC you need a higher airspeed. Declare an emergency if necessary.
Icing (especially moderate-severe icing) usually occurs in relatively narrow altitude bands. Once you start the approach, you will more likely than not descend out of the icing you had at holding altitude.