John,
I wasn't thinking so much about time, purely, as the extra distance. Look at Heathrow to Mildenhall to Southport on a map. That's two sides of a triangle to Birmingham. It's not a "detour" as much as a re-routing. How many other great courses come into play with a 2 hour re-direction between LHR and Southport? Loads: obviously all the London Heathland courses will ass less than 2 hours to the driving, even if heading in the wrong direction, Ganton, Alwoodley, Notts - Beau Desert is practically on the route. I love Royal Worlington but it seems a really off the wall suggestion as an add on to a North West England trip.
I'm all for travelling for golf - I'm the guy who took the redeye from San Francisco to Milwaukee to join the Lawsonia Links Mid-West Mashie, remember, as an add on to a trip to California. So I get where you're coming from.....