We've stayed at all levels and had the different amounts. Only once, when we were at the Polynesian did we have any issue with our preapproved amount. Our last night there, we stopped off to buy dd a sweatshirt since it was chilly. The charge wouldn't go through because we were 'over' our preapproved amount. We paid with a credit card and went on our way. They told us back at the Polynesian that all we had to do was resubmit our card for another amount. Since we were leaving that day we didn't.
But, and this one was a shocker....when we were at BWV last Thanksgiving, we used dh's Amex card, since we had put cash aside for the trip, we would pay the balance when the bill came. No problem...except on the day of departure, when they tried to put the charge through (for about $1300) Amex wouldn't accept it. Seems they have a policy of only okaying charges of $500 a day!!! At least that is the policy with this particular business acct. So, we got a bill from BWV/DVC about a month later, which we promptly paid. But...I guess my point is to be sure your particular credit card doesn't have a daily charging limit on it. I know my debit card used to have one.