Not so much a house swap, but house sitters required to feed three Burmese cats and 7 chickens - you get the eggs too, over the Christmas period.
4 double bedrooms (3 cots, all baby stuff, prams, highchairs, toys, etc in a large nursery room - my workplace!)
Drive for 7 cars, large safe garden, all mod cons. 20 mins on the train from London, lots to do, visit and see.