Martinidoc.
Whilst I know what you mean about the Westminster, I think you may be being a little too harsh. The fixtures and fittings are new and in great shape.
The main thing that drags it, and other parts of Le Touquet down are the crowds of loud football-shirt-wearing Brits on holiday.
The Chateau de Montreuil is superb, but it certainly isn't convenient for Le Touquet if you intend to combine the beach, and some shopping with your stay.
2D