It's sad really. I'm in the UK in the second week of October and I need to go to Bath (100+ miles West of London) - it's a 90 minute train ride and a 2+ hour drive. No contest really. It's a little more tricky doing the next leg in the trip, which will be Bath-Winchester, but managable. I'll probably use a car service to actually get me back to Heathrow because it does tend to fall apart at that point.

Winchester-Waterloo-tube-Paddington-Heathrow Express is a little bit too painful for me.