Yep, I've done that too, but most of the check in clerks haven't wanted to take them before charges have posted. I usually apply gift cards to the balance every couple days, and finish up day before checkout. I don't think the op needs to worry about getting her credit card charged, I wanted to make sure she knew if for some reason that happened, it is fixable.When I have checked in using gift cards, I simply gave them the gift cards at check in, and they used them first before billing my credit card.
Last week, we checked in Friday evening. I kept a close eye on my cards to see when I got charged. I checked both cards several times during the day. We knew we would be checking in late because we were going to visit an Adventure by Disney guide friend who had had a major car accident and had just gotten out of the hospital. After we took her dinner and visited, it was close to 830p before we checked in. Talking to the evening front desk manager, they explained the process and that they do not charge as they do not know for sure you will show up, and the specific room you are assigned can change up until you are actually checked in. If you are a no show, they simply keep the deposit you have on file, but do not bill you for the remaining nights.I will ask more questions this weekend.