To cook that amount of chicken takes several roasting or lasagna pans. When I wash the chicken parts I do try to remove the biggest globs of fat so I can just set the chicken quarters on the floor of the pans. Don't crowd the leg quarters.
Washed, trimmed of fat, with salt and pepper on them, the quarters bake up tasty and moist at 400°F for 45-60 minutes. Check the internal temperature of the thighs to assure the chicken is fully cooked. The USDA recommends cooking chicken until it reaches 165°F.
When the chicken is cool enough to handle, it's time to "disassemble" it. I sort it into three piles:
- bones headed to the stock pot,
- skin & fat headed to the trash, and
- meat headed to the freezer in meal-sized zipper bags.