Ok...breathe. It's not the end of Christmas.
I'll share a story with you. It's not a Christmas one but it does have some similarities.
When my fiance and I gave out invitations to our engagement party, out of a total of 12 invitations, 4 gave an RSVP. Some figured it would be okay to tell us their decision on the day. So eventually, eight people came after we did the chasing around, and even then six people came to the dinner. We decided to tell the ones that said that they would get back to us on the day that they were no longer invited.
In the end, it was a fantastic night shared by close friends.
Christmas is the happiest time of year and it is also the most depressing time of the year. It's a time for togetherness and sharing but not all people feel that they can contribute anything to the season. Try not to feel hard done by your friend that doesn't want to attend the dinner. You could try to arrange it with the others to help pay for his meal and then approach him to invite him out.
It sounds like you want him to be there as well so his presence can be his present to you and the others while his dinner is his present. So what if he doesn't spend anything, Christmas is about being able to share happiness and joy with other people, especially the people you care about.
Just my two cents.