I too think Orlando water is terrible, but cheap. Now, I don't want to bring a Brita gallon container with me when I go due to packing space considerations, but I think the following items might be useful.
Pur Faucet Mount Filter $19.99
Brita On-Tap Faucet Filter $34.99
Both of these could simply screw onto the faucet in the normal
DVC rooms. You could use them to fill your bottles every night, make coffee, baby bottles, etc... Then, at the end of your trip, screw if off, and take it home.
The last item here is something like a regular sports water bottle, but with a filter built in. You could refill these with the cold water from the water fountains in the parks.
Brita Fill-And-Go Water Filtration Bottle $7.99
I hope this helps somebody. Also, if you've tried, feedback would be great. (for example, can you actually screw these onto the DVC property faucets?)