If you do go round the outside remember that there is a convenient VRP (Bagshot mast) on the corner of the Heathrow zone. If you route to the south and west of the mast you will be outside of the zone, and as long as you stay close you will be clear of the Farnborough and Blackbushe ATZs. As long as the viz is reasonable this is easy to do VFR. Stay clear of the danger areas mentioned by FFF though.