Am I likely to get cooperation from Farnborough, the route takes me through their overhead, or should I route around the MATZ?
They're very good at any time, but on a mid-February weekday the airwaves are unlikely to be crowded and you should have an excellent service from them.
If you want an even more direct route which is a little different then give Heathrow a call on 125.62 and see if you can get a special VFR transit via BUR and Ascott. You shouldn't have too much competition for that tomorrow either.