I think rather not say on a forum. I'd never be able to afford it nowadays and even ten years later we still have to make a lot of sacrifices to afford it (no new cars, haven't been on holiday for five years, still can't afford to do much work on the house, etc). Yes there would be some margin after downsizing but the amount I'd be giving away to solicitors and in stamp duty would hurt. A lot. It would be like tipping a years salary down the drain.
Relocation completely out the question? Seems like such a solid position to be in, though perhaps that's why you don't want to change!