DCL is offering transfers for London City Centre to Dover. You don't need to book a hotel with DCL to use this transfer. The pick up point is the Doubletree Victoria. We are staying at a Premier Inn around the corner from there. It doesn't look like the Premier Inn we are staying at has a room for four, but the Premier Inn Waterloo and County Hall do and they are close by. There are lots of Hotels in the area including a Comfort Inn.