I think this is one of those questions that poses so many different answers. Simon hits the nail on the head , it depends upon your attitude to risk.
Undoubtedly the most comprehensive cover is provided by a separate Continental Touring Policy from RAC/AA , they really leave nothing to chance , and as Stephen has commented the RAC will waive the 10 year cut-off date for us. If I am doing a long trip deep into Europe , then that would be my choice.
There are several companies who offer "bolt-on" modules as part of your UK insurance (Gott & Wynne, Headley etc) and these are generally serviced by an organisation like Green Flag or similar.
Then there are "freebie" policies that come with bank accounts etc. If was just going somewhere in N France like LMC or Monthlery, then I would be happy to use those, but I wouldn't be expecting them to provide a similar level of service to the 5 Star policies of the RAC/AA.
Breaking down in a Morgan is pretty stressful experience at the best of times, so anything that can remove that worry and give you peace of mind, is well worth it in my book.
