For those with extra time:
When you pour the duck stock from the roasting pan, replace the pot with a tall pitcher instead.
Cool it down (e.g., 30-60 minutes in the freezer), and the fat will settle at the top and solidify. You can now easily remove the fat with a spoon and, for example, use it for frying another time.
Reduce the duck jus to half, and it can now be used for a sauce. Since there is no fat in the jus, I recommend making a roux-based sauce instead:
Melt 2 tbsp butter in a pan and add 2 tbsp wheat flour. Whisk well and then add your duck jus along with cream and the reduced wine. Continue whisking and season with salt, pepper, lemon juice, and gastrique.