My IL's got their dog from the same shelter I think, and apparently they are very good. Have you spoken to the shelter about your situation? I know it might be hard to go and do (better to go there if you can, than do it over the phone), but I think its worth a try talking to them and seeing if kitty can board there. I have seen this happen at the Lost Dogs home in North Melb for a bunch of dogs. They were boarded in pens next to the adoption centre. Discuss payment if you are able to pay something, or make an arrangement to donate your time?

I'm sorry I can't look after the cat, as much as I would like too.

I hope it all goes well.