I find it interesting that Lewis believed in purgatory. As you know, I have been reading a lot of his stuff lately. I think this belief is evident in The Great Divorce and even when you look at his high view of George Mac Donald. I say this only because there was a little bit of a purgatory-like thought (at least I thought, but I am not some literature expert) in his book, Lilith.
I think that thinking about this subject is almost giving too much thought to what will happen when we die because frankly, we do not know what it will look like, what it will feel like, etc. I think sometimes that things are better left mysteries because our simple minds can not possibly contain the sort of high knowledge God has. I am not saying I agree or disagree!