If it was me, I would put the kitchen in the dining room, would be lovely big kitchen with large table in it. Then I wouldn't need separeate dining room. Would use current kitchen as utility and conservatory as family room/playroom/study/ second living room
There is plenty of space, it is currently badly designed.
But actually, the kitchen space isn't that small, if you empty all their stuff out and think about it a bit, you can fit a lot into a small space if well organised