I always go with Lydd too, it's the easiest to get a word in with.
I have on several occasions done a practice PAN with D&D on the way back from Le Touquet, just after crossing the FIR. From 4,500 feet, RT is S5. Every time, they've been able to give me a position fix based on triangulation, sometimes with only two sites as it's right at the edge of their triangulation area. Their fixes have always been accurate.
If you are up nice and high if/when your problems start, you'll have plenty of time to get a call in to anybody you like. If you insist at crossing at 2,000 feet, as some people do, it will be a different story.