RAC will not recover a broken trailer according to RYA when asked.
RAC - If your trailer breaks down within the UK, we will attempt to repair it at the roadside. This could either be a permanent or temporary repair. However if the trailer cannot be repaired, we will not recover it.
I get the feeling the sales departments will tell you pretty much anything, hang phone up and call claims line and ask them maybe worth doing.
As I said before, the 7m is not counting the drawbar but the breakdown companies count it. Last tango even posted up the DVLA wording and technically you could tow way over 7m and still be legal but it looks like breakdown companies may say you are on your own when crunch comes.
I wonder if you have caravan club membership if RAC will offer their arrival service on boats, that would fix everything as no limits apply-
https://www.rac.co.uk/breakdown-cove...anandmotorhome
Looks like there may be some mileage in that route as they mention trailers are covered-
The Camping and Caravanning Club. Your cover includes everything standard RAC breakdown cover offers together with specialist benefits to cover your caravan, trailer tent, motorhome or trailer