I don't understand the reluctance to do "trekking west". After all, isn't that what the Tube is for? And it's not as if you're a commuter who treks into work on every working day.
If a WG is worth it, then visit her. Most of the independents either do incalls or book a hotel room for the days they decide to work, which is sometimes in an area around a railway station such as Euston or Kings Cross, which was always fine by me as getting there was no problem at all.