i know you get 6 months of 0% interest on a Disney vacation with the Disney Visa, but does that apply to trip balances or only if you pay in full at booking?
It can be any part of your total but it must be a qualifying purchase which would be a package (room + tickets) or a Disney cruise. Any payment you make must be at least $101 but I'm not 100% on that. Might be $100.
Purchases charged to your room while on vacation or room only reservations don't qualify.