7 to 8000 above profile? How far from the airfield? The best you will safely achieve ( stable rod and thrust at 1000' agl) in any boeing is double the profile at 10 nm flown with flaps 25 gear down on 737 170 and gear down flaps 20 on 747 classic and 744 160knots. You will get a rod of 1500 or so and visually will see the aimpoint well short of the threshold until you are in the 3 degree slot. So that means 3000 above profile at 10 nm and configured. An extra 10 track miles doesnt mean an extra 3000 feet unless you are similarly configured. Racing towards the ground at high speeds is a problem unless you have greater than a 6G rating on your aircraft. If ATC is the problem then time to make a phone call and have a cup of tea to mutually understand each other then work out somewhere to orbit or race track and descend. The fuel considerations are minimal as you burn 40 kg a minute in a low level pattern of 4 minutes equals 160 kg. You only burn 300 kg in a complete descent so an idle descending holding pattern or orbit costs zip. regards