Thanks everyone!
Unfortunately we only have Nov. 15 - 19 (really 18th since we should leave early on the 19th to spend the day in Nara) so I'll keep an eye out for cancellations but it's a drag that I didn't plan this earlier. Re. photography, I would assume it's allowed judging by the many Google Images and photo blogs I've seen. I'll take your advice and try in person if we can't secure them online. The thing is, our concierge went in person (how great is service in Japanese hotels?!?) with our passport numbers and personal info and was unable to secure anything. I've actually read that Shugakuin is more interesting and many enjoy it more, especially for koyo viewing. I was still really set on Katsura though... oh well. Hopefully we'll be able to squeeze in a last minute appointment while in Kyoto.