There are a few times a year when civilians (not cast members) can dress up. And that's mickeys not so scary Halloween and a few other events. If you move to FL and become part of the FL501st we are able to troop at Disney for certain events....though I don't know if they allow Fett because of the Disney owned Fett. (I cant remember maybe
Sparrow Fett can tell us... hes actively trooping and theres a SW marathon next month so they'll be trooping that).
I live in FL and am an annual passholder.... you DO NOT want to ever dress up in a fett for Disney.
1. Have you tried sitting down in your Fett? Its a burden....
2. You cant ride the rides in your Fett
3. Its hot in FL... even hotter in the Fett suit.
Moral of the story if you end up going to one of those events. Wear a TDH shirt... or get a soft costume like a Sith or Jedi.... its not worth the hassle of dressing up in Fett a TK or anything with lots of armor. UNLESS youre trooping and get in free its VERY pricey to get in the park why ruin your families fun to parade around in your suit(they may not say anything but they'll be aggravated by stopping for photos every other second).