You may end up paying more with two one-way rentals.
When you make one-way car rental reservations, you have to specify your pick-up and drop-off locations.
The rate is often different than that's available when pick up and return at the same location. Often coupon codes are not valid for one-way rentals.
Although the traditional "one-way drop charge" is now rare, you're likely to find either a much higher daily rate or a rate with a per-mile charge in addition to the daily rate (instead of unlimited miles).
Sometimes you can get a great deal in one direction. When rental car companies need to adjust their fleets, such as moving cars north or south to reflect seasonal tourism patterns, you can find rates for next to nothing. But this requires luck and is likely to help you in only one direction.
You may find that your best bet is to keep the car while you're Florida. That way, you can rent and return at your home city (using the best rate code and coupon code you can find), and you'll have the benefits of a car while you're at WDW. With major car rental companies, geographic restrictions within the United States are rare, although you'll want to confirm that the unlimited free miles are good for driving throughout the United States.
To answer the actual question, Disney-owned WDW resorts do not have car rental counters, but cars are easy to return and/or rent on or near WDW property, with courtesy service between your resort and the rental car office. There's a "sticky" at the top of the DISboards Transportation forum.
