We offered that we'll cook, or BIL can (he has insisted on previous years), or they can have just the PIL and we'll do something else. Suggested they could pop over Xmas Eve instead if they prefer. We can't order meat when we don't know if we are cooking for anything from 0 to 11 people. Or if we are going, what dish we need to order for. Two weeks and still they "are thinking about it". It seems really late to me for ordering, AIBU to just go ahead and order food assuming we have the PIL and other siblings but not them, or should we wait longer?