I can recommend Beachborough Park. It's a quiet country house that does bed and breakfast and is literally less than half a mile from the channel tunnel entrance.
It's down a country road and then a long private driveway - so there should be almost zero chance of a casual thief making off with your pride and joy.
It's only a couple of miles from me and friends of my parents have stayed there before travelling through the tunnel, they said it was excellent. Here's a link for more info:
http://www.cornerpubs.ndo.co.uk/beachborough/