As you know you cannot have the pet in the unit. I probably wouldn't board at a WDW kennel. They're mostly dogs, (if not 100% dogs), and that might be traumatic for a kitten. If you want to board, you might do it at a kennel near your home. Maybe one that wouldn't have much traffic in and out and might be a littler quieter.
That said, I personally would not worry about the kitten staying home alone for a week. We've had cats for 35 years now, and have left them home alone on numerous occassions.
Decide which rooms the kitten would be allowed to use, and close and block all other doors so the kitten can't accidently get locked in a different room.
Make sure the room has at least one window with a ledge or piece of furniture the kitten can get on and look out the window.
You might go to the pet store (or Wal-mart etc) and get both a dry feeder and a water bottle feeder that automatically replenish the bowl as food/water is consumed. Make sure the water bottle cannot be tipped over while you are gone. (We always put down a deep bowl of water as an emergency backup in case one gets spilled) The dry food should be for a kitten. Do not get adult food.
You'll want more than one litter box. You can temporarily use a cardboard box, cut down, and filled with litter. Make sure the bottom of the box is lined so liquids will not soak through. Or just get several plastic litter boxes. (We actually use a Litter Maid automatic litter box which works fine for a week or more)
Make sure the kitten has something to scratch on. Don't keep him/her in a room with good furniture.
Make sure there's a comfortable place to sleep.
If there's some toys around, leave them available. The kitten will have much more energy than an adult cat and will need to entertain themselves more.
Be sure you set everything up well before you go so the kitten has several days getting use to the setup you've made, while you're still there.
Cats and kittens are very independent. After about a day they'll start their own routine. You should be fine.