If you've got the nerve to wait, you'll almost certainly find that as the witching hour approaches, you'll get some good and serious bids.
Basically, from a WG's POV she'll wait to get full-price gigs from punters contacting her. As your start-time approaches, you will become the preferred option because she'd rather be with you on a cheaper rate, than sitting on her arse doing and earning nothing.
If you're in a nice hotel in London, you'll almost certainly get some good bids from well-regarded WG's. I wouldn't mind betting a few girls have already seen your RB and have you on the backburner.