I was able to book during the disney visa holders time. I do not have a disney visa, but my SIL does and we were able to use it for the deposit only. I then paid the remaining balance on my bank card. When we asked the CM said he was not sure and went to ask. He came back and said that it did not matter if she was staying with us or not, just that it needed to be booked with a disney visa. We did do a three way call and she gave her info to the cast member.
Hope this helps