That's not quite the range of the Phantom 3 Professional, which managed 2,500 feet without issue, but it's better than the 1,000 feet I got with the Phantom 3 Standard in open space and the 400 feet it managed in suburbia.
Medical specialists with a public voice like Dr. Oz should absolutely be encouraging people who are sleepy to sleep more. However, arbitrarily applying eight hours to everyone is actually harming people who simply need less sleep, or those who actually need more than eight hours.
Next, do not set an alarm clock. Sleep until you wake up naturally. If you are like most people, you will probably sleep a long time that first night, maybe even 16 hours or more. This is because you are in a situation called sleep debt.