What does it matter how big the turkey is and how few are there on Christmas day, surely you all have freezers?
Work out how much will be needed for the next few days then dismantle the turkey, wrap it up in portion size packages, depending on family size. I wrap up portions for two and put them in the freezer to be used in a variety of meals over the next few months, then put the carcass in a big pan with water and a few veg and simmer for two hours to make stock, portion that up and freeze for later use for soup or gravy.
What to do with left over sprouts? Freeze, slice and fry in butter with parmesan cheese. Put in turkey stock to make soup or...
... make Christmas Pie. Put in a pie dish all the bits left over from Christmas day: turkey, ham, sausagemeat, stuffing, roast potatoes, parsnips and sprouts. Make a thick gravy from turkey stock to cover, cover with pastry and bake.
DS and family will arrive soon and we have a second present opening tomorrow. As I cannot do another turkey lunch I asked DGC what they would like and with one accord they shouted 'Christmas Pie', so that is what we will have, although I did have to roast extra potatoes specially as all the Christmas day potatoes were consumed.